Benign Bone Tumor

In simple words, a bone tumor which is non-cancerous i.e. which does not have the potential to spread to other regions of the body or invade other local tissues is called a benign bone tumor

Benign bone tumors are far more common than malignant (cancerous) bone tumors.

Benign bone tumors are far more common than malignant (cancerous) bone tumors. In fact, their exact number or percentage in the population cannot be reliably estimated,as a large number of them are asymptomatic and henceremain undetected, i.e. they do not cause any sort of trouble or discomfort to the person, who may therefore, live a normal life without realizing he/she has some bone tumor (someare more appropriately called as tumor-like conditions as they do not represent true tumors). At this point, it is important for you to understand that a lot of these asymptomatic benign tumors do not require any kind of treatment, and consequently, it is perfectly fine if they remain undetected. Although a large number of benign bone tumors may never require treatment, it is quite common for some of them to become noticeable or cause symptoms in the form of pain, swelling, restriction of joint function, etc. This may sometimes necessitate symptomatic medical treatment, or surgery. Some types of benign bone tumors are known to be aggressive by nature, e.g. Giant Cell Tumor (GCT) of bone. These tumors always need treatment, which in most cases is in the form of surgery.

Benign bone tumors can affect any bone. Nonetheless, they are most commonly found in the large bones like the femur (thigh bone), tibia (large leg bone), humerus (arm bone), pelvis, etc.

Benign bone tumors can affect any bone. Nonetheless, they are most commonly found in the large bones like the femur (thigh bone), tibia (large leg bone), humerus (arm bone), pelvis, etc. However, some benign bone tumors more commonly involve certain other regions of the skeletal system, e.g. Enchondroma most often affects the small bones of the hands and feet. Certain benign bone tumors affect specific locations in the long bones, e.g. GCT of bone most commonly affects the lower end of the femur, upper end of the tibia or upper end of the humerus; and in all cases, this tumor is found in close proximity to the adjacent joint. Osteochondroma is always found on the surface of a bone, growing in a direction away from the adjacent joint. Thus, a lot of these benign bone tumors have their own singular appearance on an X-ray, displaying their peculiar behaviour and typical location in a commonly affected bone of a patient in a particular age group; all of which are powerful clues to the likely diagnosis of the condition.

Benign bone tumor can affect anybody. A large number of such people may be asymptomatic. Some persons may be affected by a symptomatic benign bone tumor or an aggressive benign bone tumor, both of which calls for attention and requires treatment. There is no reliable way to identify people at risk of developing a symptomatic or aggressive benign bone tumor, as in most cases they occur spontaneously, without any known cause. They can occur at any age. However, most of them are noticed in the first four decades of life. Rarely, certain benign bone tumors can occur as an inherited disorder, or as a part of a syndrome.

Benign bone tumor can affect anybody. In fact, a more accurate way of putting it is, “Benign bone tumor can be present in anybody, and it can affect anybody”. This means, there are a number of people who may have a benign bone tumor (more appropriately called as a benign bone lesion, as a large number of them are not true tumors) but are unaware of it as it is not causing any symptoms (and is quite likely to remain so throughout the person’s life); whereas some persons may be affected by a symptomatic benign bone tumor or an aggressive benign bone tumor, either of which calls for attention and requires treatment. Nevertheless, there is no reliable way to identify people at risk of developing a symptomatic or aggressive bone tumor, as in most cases they occur spontaneously, without any known cause. They can occur at any age. However, most of them are noticed in the first four decades of life. Specific benign bone tumors are often noticed in typical age groups. For example, GCT of bone is unusual in childhood; it is most commonly noticed in the 3rd and 4th decade of life. Simple Bone Cyst is usually noticed in the first two decades of life while ChondromyxoidFiborma is typically seen in the second decade.

Rarely, certain benign bone tumors can occur as an inherited disorder, or as a part of a syndrome. In such cases, the patients usually have multiple benign bone tumors affecting different bones. These conditions are rare. A classic example of an inherited bone tumor condition is Osteochondromatosis, also called as Hereditary Multiple Exostosis (HME) or DiaphysealAclasis. In this condition, the person develops multiple osteochondromas (bony outgrowths capped by a layer of cartilage) from the bone, affecting multiple areas of the skeletal system. This is an autosomal dominant inherited disease. McCune-Albright syndrome is a rare spontaneously occurring non-inherited genetic disorder where the patient has Polyostotic Fibrous Dysplasia (a bone disorder), abnormal skin pigmentation called Café au lait spots/patches, precocious puberty and other endocrinopathies due to autonomous endocrine hyperfunction. Maffucci’s syndrome is another rare congenital, nonhereditary disease where multiple enchondromas (benign tumors made of cartilage, formed within a bone), are associated with multiple hemangiomas (a benign tumor made of blood vessels). Not all of these multiple benign bone tumors in these disorders need treatment as many of them do not cause significant problems. As such, it is not possible to surgically treat all of them. However, sometimes, one or more of the benign bone tumors in these patients may cause problems like a pathological fracture, mechanical obstruction of a joint, pain and swelling due to large size of the tumor, etc., in which case treatment becomes essential. Nevertheless, the real hazard to these patients, especially for those with multiple cartilage tumors, is the significant risk of one or more of their bone tumors transforming into a sarcoma.

When symptomatic, the symptoms of benign bone tumors are no different from that due to malignant bone tumors. The most common symptoms are pain and/or swelling. Some patients may present with a pathological fracture. A bone tumor in the region of a joint often causes restriction in the range of movement and function of the joint, either due to a mechanical obstruction caused by the swelling or due to pain.

When they cause symptoms, the symptoms of benign bone tumors are no different from that due to malignant bone tumors. The most common symptoms are pain and/or swelling. The pattern and nature of pain is highly variable. Some of the benign aggressive bone tumors may show a rapid evolution in the intensity and duration of pain, quite like that of a malignant tumor. Many patients may report having a swelling for a long time, which has remained unchanged in size and shape. In a number of these cases, the swelling may be painless and may remain so indefinitely. In patients with benign aggressive bone tumors, the swelling may show rapid growth along with associated pain, which may eventually become distressing. Such a situation may cause suspicion of a malignant process. Some patients may present with apathological fracture. This is often seen in cases of benign aggressive bone tumors like GCT of bone, ABC of bone, etc. or in cases with cystic or fibrous tumors of bone like Simple Bone Cyst, Fibrous Dysplasia, etc. In some cases this fracture may occur through a joint (called an intra-articular fracture). Besides the possibility of an intra-articular fracture, a bone tumor in the region of a joint far more commonly causes restriction in the range of movement and function of that joint, either due to a mechanical obstruction caused by the swelling or due to pain.

However, as already mentioned earlier, a large number of benign bone tumors are asymptomatic and may be detected only incidentally when an X-ray of that region is taken for some other reason, e.g. for an injury, etc.

In such an event, the most important thing that you must do is, speak to your doctor and consult a bone tumor specialist.

However, in the meanwhile, there are several things that you must NOT do. They are as follows:

• Do not massage the swelling under any circumstance. This is because, if it is a malignant tumor, massaging could cause some of the tumor cells to be released into the blood circulation or the lymphatic system, through which they could travel and lodge in some distant organ or tissue and form metastasis. Besides, massaging will not offer relief in the presence of a tumor; it could actually aggravate or trigger the pain. It can also cause a pathological fracture.
• For the same reason as above, do not apply any sort of compression bandage over the swelling. Also, avoid touching and examining the region frequently.
• Do not attempt or allow, any sort of chiropractic manipulation of the affected region. This could be dangerous in the presence of a bone tumor. Besides the risk of releasing tumor cells into the blood and lymphatic circulation, it can also cause a pathological fracture.
• A bone with tumor generally does not have the strength of a normal bone as most tumors tend to weaken them; which means such a bone is at a risk of fracture following trivial events like lifting a heavy object, a fall at home, walking, etc. (pathological fracture). Hence all precautions must be taken to avoid the possibility of such a fracture. It is best to follow the following guidelines till your doctor examines you and decides what level and what kind of activity is safe for you:
  • Avoid unnecessary use of any limb which is painful or has a swelling.
  • Avoid any activity which triggers or aggravates the pain.
  • Do not attempt to lift heavy objects.
  • If the tumor is in the lower extremity, avoid putting weight on that limb while walking or standing. Use a ‘walker frame’ if necessary.
  • Avoid falling, at all costs. Any kind of local injury, in the presence of a bone tumor, carries a significant risk of causing a pathological fracture. This often happens where and when you least expect it – ‘at home’. Most often, this happens in the toilet or the bathroom due to a slip on the polished floor tiles, which may be wet and therefore, slippery. These are also situations when you are generally alone. Seek assistance while ‘going to’ and ‘coming from’ these places. Beware of wet floors. A pathological fracture, besides causing intense pain and serious disability, also complicates the treatment of the disease.
• Avoid all sports which may involve physical activity, unless your doctor considers it as safe for you.

Certainly not. This is not a contagious disease or any sort of infection. There is no health risk to any member of the family whatsoever.

A large majority of benign bone tumors occur spontaneously, without any known cause. They are either found incidentally while investigating for some other problem, or when they cause symptoms. However, there are certain rare benign bone tumor conditions, which have known genetic cause, some of which may also be part of a syndrome, e.g. McCune-Albright syndrome, Hereditary Multiple Exostosis (HME), etc. Overall, with the exception of genetically inherited disorders like HME, the risk of a blood-related family member developing a similar disorder is the same as that of an unrelated person from the general population.

A large majority of benign bone tumors occur spontaneously, without any known cause. They are either found incidentally while investigating for some other problem, or when they cause symptoms. However, there are certain rare benign bone tumor conditions, which have known genetic cause, some of which may also be part of a syndrome, e.g. McCune-Albright syndrome, Hereditary Multiple Exostosis (HME), etc. There also are some other rare benign bone tumor conditions where the exact cause is not known, but a genetic cause is suspected, e.g. Multiple Enchondromatosis (Ollier’s disease), Maffucci syndrome, etc. An interesting feature of these benign bone tumor conditions is that they are associated with the formation of bone lesions in multiple locations in the skeletal system, i.e. the patient has bone tumors in many bones. In a particular condition, all these bone lesions are of the same kind, e.g. in HME, all the different tumors are Osteochondromas; in Mafucci syndrome, the bone tumors are Enchondromas; etc. Despite having a known or suspected genetic cause, a majority of these disorders (with rare exceptions like HME) occur sporadically, i.e. they are not inherited and therefore, do not indicate an increased risk of a similar condition developing in any blood-related family member. Most of these conditions are clinically obvious in early childhood.

A rare but well known example of an inherited bone tumor disorder is HME (Hereditary Multiple Exostosis). This is an autosomal dominant disorder which causes the formation of multiple osteocartilaginousexostoses, which are benign outgrowths of bone capped by cartilage. Due to the occurrence of multiple tumors in this condition, one or more of which may undergo a malignant transformation, it poses a significant risk to the patient, of developing a sarcoma. Similar risk of developing a sarcoma (for a similar reason) exists in some of the other benign bone tumor conditions mentioned earlier, e.g. Multiple Enchondromatosis (Ollier’s disease), Maffucci syndrome, etc. Overall, with the exception of genetically inherited disorders like HME, the risk of a blood-related family member developing a similar disorder is the same as that of an unrelated person from the general population.

A benign bone tumor is often discovered incidentally in X-rays which are done for some other reason, e.g. following an injury, etc. Besides that, a benign bone tumor is most commonly detected when a patient reports to his/her doctor with some unusual pain or swelling in his/her body. Uncommonly, some patients may present with a pathological fracture.

Besides being discovered accidentally in an X-ray or some other radiological imaging done for some unrelated complaint (hence called as an ‘incidentally found’ bone lesion), a benign bone tumor is most commonly detected when a patient reports to his/her doctor with some unusual pain or swelling in his/her body. Uncommonly, some patients may present with a ‘pathological fracture’. A detailed history and clinical examination helps in localizing the problem and also in deciding the further line of investigation. The simplest and most important investigation to detect and identify a benign bone tumor is a regular plain X-ray. The other investigations of value are MRI, Bone scan, CT scan and PET scan. However, all these investigations are generally done, if necessary, after viewing the X-ray. The need for these other investigations will be decided by the doctor treating you.

The foremost thing you must do is consult your doctor, when you notice any unexplained swelling on your body (even if it is painless and does not cause any discomfort), or have some unexplained pain, that refuses to go away or is increasing in duration and/or intensity. It is best to investigate these complaints early, as earlier these problems are detected and managed, better is the benefit of treatment (when indicated). Moreover, it is important to remember that malignant bone tumors present with exactly similar symptoms, and in these cases, delay in detection of the disease and its treatment can have serious consequences.

Diagnosis of a benign bone tumor is done in the same way as that of a malignant bone tumor; i.e., by clinical examination, blood investigations, radiological studies (X-ray, MRI, etc.) and pathological investigations (biopsy, etc.).

Diagnosis of a benign bone tumor is done in the same way as that of a malignant bone tumor; i.e. by clinical examination, blood investigations, radiological studies and pathological investigations. In some benign bone tumors, which are clearly identifiable on X-ray (especially in cases where treatment is not required), biopsy is not necessary. There are some benign bone tumors that may be treated without biopsy, as their clinical presentation and radiological imaging are so typical that it cannot be any other condition, e.g. Osteoid Osteoma, Osteochondroma, Simple Bone Cyst, etc. However, there are many other situations where a biopsy is mandatory; like for example,

• 1.When the disease appears aggressive in nature and has caused bone destruction,
• 2.When the clinical presentation and radiological appearance of the tumor is not conclusive, and treatment appears essential,
• 3.When it is suspected that it could be a malignant disease, or a malignant transformation in a benign condition, etc.

Biopsy is a minor surgical procedure in which a small piece of the tumor tissue is sampled and sent for evaluation to a pathologist, who examines it under a microscope to establish its exact histological identity/name (diagnosis).

One of the most important pieces of information sought with a biopsy is whether the disease is a benign or a malignant tumor. All biopsies should be planned assuming that the lesion could be a primary malignant disease. This biopsy planning is very important because an improperly done biopsy can affect the future treatment of the bone tumor, especially if it turns out to be a bone sarcoma. Biopsy is therefore, best done by a surgeon who is specialized in bone tumor treatment.

Biopsy is a minor surgical procedure where a small piece of the tumor tissue is sampled and sent to the laboratory for evaluation by a pathologist. The pathologist, after processing the tissue sample, examines thin slices of it under a microscope to establish its exact histological identity/name (diagnosis). One of the most important pieces of information sought with a biopsy is whether the disease is a benign or a malignant bone tumor. It is not unknown for a disease to appear benign on clinical investigation and radiological imaging, but found to be a malignant condition on pathology. It is for this reason; all biopsies should be planned assuming that the lesion could be a primary malignant disease. This biopsy planning is very important because an improperly done biopsy can affect the future treatment of the bone tumor, especially if it turns out to be a bone sarcoma. The reason for this is explained in the section on Malignant Bone Tumors. Biopsy is therefore, best done by a surgeon who is specialized in bone tumor treatment.

Several biopsy techniques are available, including Fine Needle Aspiration Biopsy, Core Needle Biopsy, Incisional Biopsy, Excisional Biopsy, etc. Biopsy for bone tumors is generally done as a small open surgery (Open Biopsy) or with the help of special biopsy needles (Core Needle Biopsy). Between the two, Core Needle Biopsy is generally the preferred method for doing a biopsy as it is a simple, reliable, minimally invasive, safe and quick procedure. The correct method for your situation is best decided by your doctor.

Core Needle Biopsy in skilled hands, offers significant advantages over Open Biopsy and therefore, it is the preferred method for obtaining tumor tissue samples.

The goal of a biopsy procedure is to obtain a sample of tumor tissue so that it can be studied by the pathologist to identify the exact nature of the disease and establish its identity (diagnosis), as treatment of any tumor depends on its diagnosis. Generally, it is possible to obtain a larger quantity of tissue sample (which makes it easier for the pathologist to process and study the material) through an Open Biopsy. However, the material obtained by Core Needle Biopsy in most cases is adequate for a skilled pathologist. In many other ways, the advantages and benefits offered by a CNB are superior to that of an OB.

As mentioned earlier, CNB is a simple, reliable, minimally-invasive, safe and quick procedure. For a table comparing CNB with OB, see the section on Malignant Bone Tumors. This table makes it quite obvious that Core Needle Biopsy in skilled hands, offers significant advantages over Open Biopsy and therefore, it is the preferred method for obtaining tumor tissue samples. Nevertheless, there may be some situations where an open biopsy procedure could be the more suitable option.

A large number of benign bone tumors do not require treatment. Generally, when a benign bone tumor causes symptoms (pain, swelling, fracture, etc.), treatment becomes essential. Locally aggressive benign bone tumors should be considered for treatment immediately, even if they are not causing any symptoms at that time. Rarely, when a malignant transformation is suspected or confirmed in a known benign tumor, treatment becomes essential.

A large number of benign bone tumors, especially those that do not cause any symptoms, do not require treatment. Generally, when a benign bone tumor causes pain or swelling, has caused a fracture, or when noted on an X-ray suggests the risk of a fracture, treatment becomes necessary. There are some benign bone tumors, which are by nature locally aggressive; in these cases, treatment should be considered immediately, even if they are not causing any symptoms at that time. Sometimes, when a benign bone tumor is found to be active, noted either clinically or on serial X-rays in the form of growth of the tumor and/or destruction of the surrounding normal bone, further investigations to confirm the diagnosis, and possibility of surgical treatment has to be considered. Rarely, when a malignant transformation is suspected or confirmed in a known benign tumor, treatment becomes essential.

There is a large variety of benign bone tumors ranging from harmless tumors - which don’t require any treatment, to some very aggressive tumors - which consistently need vigorous treatment. In-between these extremes exist a range of tumors, which may or may not warrant treatment, depending on the situation.

There is a large variety of benign bone tumors (including some bone lesions which are more appropriately called as ‘tumor like conditions’). A large number of them are harmless and may never cause any problem throughout the person’s life. However, some types of bone tumors consistently require treatment, e.g. Giant Cell Tumor (GCT) of bone, etc. These are known as benign aggressive bone tumors. Some bone tumors may or may not require treatment, depending on the situation, e.g. Osteochondroma, Enchondroma, etc. Some bone tumors probably never require any treatment, e.g.aFibrous Cortical Defect, smallNon-Ossifying Fibroma, etc.

In most cases, benign bone tumors pose no such threat. However, if they grow very large, such a possibility may exist.

In most cases, benign bone tumors pose no such threat. However, if they grow very large (which can only happen if a growing tumor is neglected), such a possibility may exist. This situation usually occurs with the aggressive kind of benign bone tumors like GCT of bone, Aneurysmal Bone Cyst (ABC), etc. This can especially be a serious issue if the tumor arises in a location which is difficult to treat, e.g. in the spine, sacrum, etc.

Some benign bone tumors, very rarely, can become malignant, e.g. enchondroma and osteochondroma may rarely transform into a chondrosarcoma. Radiation treatment of a benign bone tumor can rarely cause it to undergo a malignant change in the future. There are some other benign bone tumors/conditions, which have been occasionally noted to be associated with the formation of a malignant tumor. These are collectively called as Secondary Sarcomas.

Some benign bone tumors very rarely can become malignant. This is typically noted in Osteochondroma and Enchondroma, which can occasionally transform into a Chondrosarcoma. However, the incidence of such malignant transformation in a benign bone tumor is very low, except in some unusual situations where these tumors occur at multiple skeletal sites (like in Multiple Exostosis, Ollier’s Disease, etc.). Radiation treatment of a benign bone tumor can rarely cause it to undergo a malignant change in the future, e.g. radiotherapy of GCT of bone, in some cases, is associated with the later formation of a high grade sarcoma in that region. There are some other benign bone tumors/conditions, which have been occasionally noted to be associated with the formation of a malignant tumor, e.g. Paget’s disease of the bone, bone infarct, etc. All these sarcomas, which arise in some pre-existing benign bone tumor/condition, or are associated with their treatment, are collectively called as Secondary Sarcomas...

The most important modality to treat benign bone tumors which need treatment is surgery. Other methods of value are RadioFrequencyAblation (RFA), Embolization procedures and Sclerotherapy.

When treatment is indicated, the most important modality to treat benign bone tumors is surgery. Rarely, small and difficult to reach benign bone tumors may be treated by ‘Radiofrequency Ablation’ (RFA). In RFA, heat is generated at the tip of a probe that is inserted into the tumor under image guidance (fluoroscope or CT scan). This local heat, which is generated due to ionic agitation and resultant friction caused by a high frequency alternating current flowing through the electrodes at the tip of the probe, kills the tissues around the probe tip. Some aggressive benign tumors, which are in areas or situations where surgery is difficult or impossible, may be treated by ‘Embolization procedures’, in which the blood supply to the tumor is cutoff, by injecting or inserting materials that block blood vessels, into the blood vessels supplying them (thus depriving them of nourishment and therefore, causing the tumor to shrink or stop growing). This is done using special catheters (inserted from a blood vessel in the thigh or arm), which are guided under x-ray imaging, to reach the blood vessels supplying the tumor. This procedure may have to be repeated a few times, at intervals of weeks or months. Sometimes, embolization procedures may be done just prior to the surgery, to lower the vascularity of the tumor (reduce the amount of blood flowing through the tumor), so as to reduce the loss of blood during the surgical treatment. ‘Sclerotherapy’ is a technique very commonly used in the treatment of vascular disorders like varicose veins, hemorrhoids, etc. In this technique, a chemical irritant is injected into the affected vessel/vascular malformation. This chemical initiates an inflammatory reaction in the walls of the vein/vascular malformation and also causes the blood in it to clot. This effectively closes the vein/vascular malformation which becomes hardened (sclerosed) and turns into scar tissue, thus treating the problem. The same technique has been extended to treat vascular malformations/tumors of the bone. Sclerotherapy has been found to be useful in the treatment of select cases of ABC of bone, hemangioma of bone, etc.

There is no established role of chemotherapy in the treatment of benign bone tumors. Radiotherapy is avoided as much as possible; but it may be used very rarely, as a last resort, in some situations where all other treatment options have failed.

There is no established role of chemotherapy in the treatment of benign bone tumors. Radiotherapy is avoided as much as possible, asit can sometimes lead to the formation of asarcoma in the treated area. Very rarely, radiotherapy may be used as a last resort in the treatment of a benign aggressive bone tumor, where all other treatment methods have failed, or where no other option of treatment exists or is viable. This often happens when the disease occurs in areas, which are difficult to treat surgically, e.g. in the sacrum, spine, etc.

A variety of surgical options are available for the treatment of benign bone tumors. Generally, for most benign tumors, the standard surgical procedure employed is ‘Intralesional Surgery‘ and less often, ‘Marginal Excision’; ‘either of which may be followed by appropriate reconstruction of the treated bone, whenever indicated.

A variety of surgical options are available for the treatment of benign bone tumors. The surgical option suitable for a particular case depends on various factors, including, the type of tumor, its location in the body, its location in the affected bone, its size, the status of the adjacent joint, age of the patient, health of the patient, etc. All of these have to be taken into account before a surgical strategy is planned. Often, more than one treatment/reconstruction option may seem reasonable in a particular case. The benefits and disadvantages of every treatment alternative are considered and discussed with the patient and family, and a decision is then taken regarding the best plan of treatment. The goal of treatment of a benign bone tumor is to remove the disease completely and at the same time preserve the bone and the adjacent joint, restore/maintain its integrity, continuity and strength, and preserve/restore maximum function. Generally, for most benign tumors, the standard surgical procedure employed is ‘Intralesional Surgery’ and less often, ‘Marginal Excision’; either of which may be followed by appropriate reconstruction of the treated bone, whenever indicated.

The commonest surgery for benign bone tumors is broadly called ‘Intralesional Surgery’. Intralesional Surgery means removing the disease from within. The disease tissue is removed in pieces and chunks using a spoon like instrument called a ‘ ‘Intralesional Surgery ‘Curette’s Hence this procedure is called ‘Curettage’. However, studies have revealed that simple curettage is not enough as it has a high failure rate (failure here means local recurrence of disease after surgery), especially in the treatment of benign aggressive tumors like GCT of bone. Curettage only removes visible macroscopic disease. In all likelihood, microscopic disease tissue still remains in the bone after a simple curettage. Additional steps are therefore, required after the curettage procedure, to deal with this residual microscopic disease.

This additional clearance of the disease could be achieved by destroying the residual microscopic tumor tissue/cells using thermal or chemical means and also by physically removing the residual disease/debris using mechanical means. More than one of these additional steps may be used in a given case to ensure complete neutralization and removal of viable disease tissue and cells. These additional steps help in extending the disease clearance achieved by the curettage procedure, and hence the entire procedure is called as ‘Extended Curettage’ or Intralesional Excision.

Following an Extended Curettage surgery, the cavity in the bone is filled, to strengthen the bone. The materials used could be autograft (bone graft harvested from the patient’s body), allograft (donated human bone procured from a tissue bank), bone cement, synthetic bone graft substitutes, etc.

The commonest surgery for benign bone tumors is broadly called ‘Intralesional Surgery’.As the name suggests, ‘intra’ means within, and ‘lesion’ means abnormal tissue. Thus ‘Intralesional Surgery’ means removing the disease from within, i.e. the tumor is reached through a surgical incision, and the disease tissue is removed in pieces and chunks using various instruments. This is because, most benign bone tumors are found within the bone, either in the form of a cavity filled with abnormal tissue/blood/fluid, or as a mass of abnormal tissue. Some benign bone tumors grow on the surface of the bone, e.g. Osteochondroma, etc.; in such cases, ‘Marginal Excision’ is the surgery of choice.

One of the most useful and important instruments used in Intralesional Surgery is a ‘Curette’. It is a spoon like device with sharp edges and a long handle. Using this instrument, the tumor tissue is literally scraped off from the walls of the cavity in the bone. Hence this procedure is called 'Curettage'. However, studies have revealed that simply curetting and removing the disease from the bone is not enough, as it has a high failure rate (failure here means local recurrence of disease after surgery). This is especially true for benign aggressive bone tumors like GCT of bone. Curettage removes grossly visible, macroscopic disease. There is every likelihood that invisible microscopic bits of tumor tissue and tumor cell may still remain in the bone following a simple curettage, which could grow back and cause a recurrence of the disease. Additional steps are therefore, required after the curettage procedure, to deal with this residual microscopic disease.

These steps could be one or more of the following:
More than one of these additional steps may be used in a given case to ensure complete neutralization and removal of residual viable disease tissue and cells. These additional steps help in extending the disease clearance achieved by the curettage procedure, and hence the entire procedure is called as ‘Extended Curettage’ or ‘Intralesional Excision’. It is important to know that some of these adjuvant methods mentioned above have the potential to cause damage to surrounding normal tissues and therefore, all precautions are taken to ensure that vital tissue like major nerves, blood vessels, joint surface cartilage, etc. are protected.
Following an Extended Curettage surgery, the cavity in the bone in most cases needs to be filled, to strengthen the bone. This can be achieved using a variety of materials ranging from autograft (bone graft harvested from the patient’s body)’ allograft (donated human bone procured from a tissue bank), bone cement (PMMA –polymethyl methacrylate), synthetic bone graft substitutes, etc. Often, more than one type of filling material may be used. In some situations, metallic implants may be used in the form of plates, screws, wires, etc. to augment the strength of the treated bone.

• High-speed Burring: using a motorized high speed rotating abrasive burr (a rotating file) to break the bony ridges within the cavity and to remove a layer of normal bone forming the walls of the cavity in the bone – to remove mechanically, any stray traces of disease cells or tissue that may be present in the walls of the cavity in the bone.
• Chemical treatment: using powerful chemicals like phenol, ethanol, hydrogen peroxide, zinc chloride, etc. to sterilize the cavity walls – to kill any invisible leftover stray cells of the tumor tissue.
• Thermal destruction of leftover microscopic tumor cells/tissue:
  • Cryotherapy: subjecting the cavity walls in the bone tomultiple ‘rapid freezing’-thawing cycles‘ using liquid nitrogen‘ to destroy tumor cells/tissue‘ or
  • Hyperthermia: using heat to kill tumor cells – This can be achieved by:
  Burning the cavity walls using an electro-cautery (an electrically powered device), which generates high local temperatures.
  Bone cement (a synthetic substance known as Polymethyl methacrylate), which is very often used to fill the cavity in the bone after an extended curettage, generates high temperatures locally for a few minutes, which can kill stray tumor cells. Bone cement, when packed into the cavity in the bone is in a soft putty like state (it is prepared just before use by mixing a powder and a liquid). Within minutes the bone cement sets into a rock solid mass (thus providing strength to the bone), during which process, it releases a lot of heat.
  Burning the cavity walls with an Argon Beam Coagulator.
• Pulse lavage: using high speed pulsating jets of saline to wash off the cavity walls of all tissue debris and tumor cells.

Extended curettage reduces the chances of leaving behind viable disease cells or tissue‚ to a large extent. This, in turn‚ reduces the risk of local recurrence of disease considerably‚ and therefore‚ gives a much higher chance of success of the surgical procedure.

As we have already discussed, the most common surgery for a benign tumor is Intralesional Surgery. This basically mea ns that the tumor tissue is actually removed in fragments or pieces. There is one major hazardwith this kind of surgery. It is possible that microscopic bits of the tumor tissue or a few tumor cells may be left behind at the end of the surgery. This can pose a problem as the residual tumor tissue/cells can grow back and cause a local recurrence of the tumor at some time in the future, which could be a few months or a few years from the time of surgery. An Extended Curettage reduces the chance of leaving behind viable disease tissue/cells, to a large extent. This lowers the risk of local recurrence of disease considerably, and therefore, gives a much higher chance of success of the surgical procedure. This benefit of Extended Curettage has been well studied and thoroughly validated.

Despite all the measures taken in Extended Curettage, it still remains an Intralesional Surgery. Therefore, a small possibility of leaving behind some viable microscopic tumor tissue/cells always remains. Hence, despite an Extended Curettage procedure, the chance of recurrence of the disease exists, although the incidence is low.

No. Despite all the measures taken in Extended Curettage, the basic premise of the surgery remains the same; it is an Intralesional Surgery. Therefore, a small possibility of leaving behind some viable microscopic tumor tissue/cells always remains. This risk is even more significant in cases with large disease, where the local situation limits the use of the adjuvant methods used in Extended Curettage.

For example, in regions where the disease has completely eaten away the bone, high speed burring cannot be done as there is no bone to burr; in such thinned out areas, use of thermal and chemical methods to neutralize the disease may also have to be guarded, to avoid injuring vital tissues and structures like major blood vessels, nerves, etc. Hence, despite an Extended Curettage procedure, the chance of recurrence of the disease remains, although the incidence is low.

There are surgical procedures, which can ensure a better chance of success as compared to Extended Curettage, as far as reducing the possibility of recurrence of the disease is concerned. However, they have their own disadvantages. These procedures are called as &Isquo;Wide Excision’ surgeries. In these procedures, the diseased part of the bone as well as the adjacent joint (in cases where the disease is close to the joint) is removed en masse with a margin of surrounding normal tissue. The margin of normal tissue maintained on the tumor ensures that all the surrounding tissues which are in contact with the disease is also removed with the tumor. The chance of leaving behind disease tissue/cells is therefore, very low. Thus, the risk of disease recurrence following these procedures is certainly lower than that with Extended Curettage.

However‚ the trouble with these procedures is related to the loss of functional tissues and the problems of reconstruction, especially when the excision involves removal of the end of the bone which forms a part of a joint. In these cases, the two major options of reconstruction are either replacement with a metallic tumor endoprosthesis, or arthrodesis (fusion of the joint). Although the tumor endoprosthesis offers good function‚ these devices are subject to the risks of loosening /breakage‚ etc. Arthrodesis‚ on the other hand‚ offers a durable reconstruction‚ but at the cost of total loss of joint function. In contrast‚ extended curettage offers a very good chance of a durable‚ long-term‚ near normal to normal function‚ for the small acceptable risk of disease recurrence.

In conclusion‚ in the treatment of benign bone tumors, the long–term functional benefits offered by Extended Curettage outweigh the consequences of the small risk of local recurrence of disease. Hence‚ in the treatment of benign bone tumors‚ morbid radical surgeries involving removal of bone and joint are avoided whenever possible.

This is a situation of balancing the promise of potential benefits of a procedurevs.the nature and extent of the risks involved. There are surgical procedures, which can ensure better chances of success as compared to Extended Curettage, as far as reducing the possibility of recurrence of the disease is concerned. However, they have their own disadvantages. These procedures are called as ‘Wide Excision’ surgeries. In these procedures, the diseased part of the bone as well as the adjacent joint (in cases where the disease is close to the joint) is removed en masse with a margin of surrounding normal tissue. As the entire diseased part of the bone is removed with a margin of normal tissue, there is no contact with the tumor tissue during the entire surgery. The margin of normal tissue maintained on the tumor ensures that all the surrounding tissues which are in contact with the disease is also removed with the tumor. The chance of leaving behind disease tissue/cells is therefore, very low. This surgery thus clearly ensures a much lower risk of local recurrence of disease.

However‚ the trouble with these procedures is related to the loss of functional tissues and the problems of reconstruction. This is especially true when the disease occurs in the region of the bone close to a joint; which unfortunately is the case in a majority of the aggressive benign bone tumors. In these cases, the two major options of reconstruction are, either replacement with a tumor endoprosthesis, or arthrodesis (fusion of the joint).

Tumor endoprosthesis (megaprosthesis) are metallic replacement devices which are used to reconstruct the operated bone and joint. Thus‚ instead of a normal bone and joint‚ the patient now has an artificial metallic device that performs the same function. Although these metallic joints offer good function‚ they cannot match the normal bones and joints in durability and the range of function. Besides being quite expensive, artificial metallic joints‚ especially those which are used in the treatment of bone tumors‚ do not offer the range of movement and function that is possible with a natural joint. Another important thing to know is‚ normal bone is a living tissue and therefore‚ has the ability to adapt and heal‚ lasting for the entire lifetime of an individual. Artificial implants are made of metal and plastic‚ which undergo wear and tear and accumulate fatigue over a period of time. After a few years‚ they tend to wear out‚ loosen‚ or even break; all of which will necessitate revision surgery with a new implant. To prolong the life of these implants‚ the patient is expected to use the operated limb carefully and avoid excessive or high energy activity; in simple words‚ they are adviseda 'restricted lifestyle'.

A far less expensive and more durable option of reconstruction following these Wide Excision surgeries is &Isquo;Arthrodesis’ of the bones across the affected joint. This means that the bones on either side of the joint are surgically fused to each other, in effect, creating one long continuous bone without any joint in between. Though durable‚ this is quite a disabling option for the patients as they then cannot fold the limb (e.g. knee arthrodesis means fusion of the femur with the tibia across the knee joint. This results in a straight leg which cannot bend).

Extended Curettage‚ on the other hand‚ offers the possibility of restoration of near normal to normal function in the affected bone and joint. If successful, this functional restoration could last for many years‚ and in a large number of patients‚ it could ensure a lifetime of normal activity and function. Moreover‚ as the normal bone and joint are preserved‚ its durability is assured. In patients with intra-articular pathological fracture (fracture through the joint)‚ and those with deformation of the joint surfaces‚ the recovery of range of motion may remain incomplete. Despite this functional limitation anticipated in such cases‚ Extended Curettage is still the better option of treatment‚ as retaining the natural bone and joint offers superior long term benefits.

Recurrence of a benign bone tumor in most situations does not pose any major risk to the patient (unless it is neglected‚ or the tumor is in ‘difficult to treat’ areas like spine, sacrum, etc.); unlike malignant bone tumors, where recurrence of the disease seriously affects the patient’s chances of survival. Recurrence of a benign bone tumor, when detected in time, can be treated easily with repeat ‘Extended Curettage’. It would be unfair to make a patient endure a lifetime of restricted lifestyle or serious disability, to avoid the small risk of recurrence of disease, when there is an alternative, which for allowing such an acceptable risk, offers many years, or even a lifetime, of near normal to normal function.

In conclusion‚ in the treatment of benign bone tumors‚ the long-term functional benefits offered by Extended Curettage outweigh the consequences posed by the small risk of local recurrence of the disease. Hence, in the treatment of benign bone tumors‚ morbid radical surgeries involving removal of bone and joint are avoided whenever possible. In situations where Extended Curettage is not possible, e.g. in cases with large disease that has eaten away the bone completely or has destroyed the adjacent joint‚ Wide Excision of the diseased part of the bone and joint may be done‚ followed by appropriate reconstruction‚ often using suitable tumor endoprosthesis or sometimes with arthrodesis.

On the other hand, in the management of primary malignant bone tumors (sarcomas)‚ however‚ Wide Excision of the diseased bone and joint followed by reconstruction using megaprosthesis (or rarely‚ arthrodesis)‚ is the standard option of treatment. Curettage surgeries are absolutely contraindicated in the treatment of bone sarcomas.

If the recurrent disease in a treated case of benign bone tumor is detected in time‚ it is often possible to do an Extended Curettage again and deal with the problem. However, if repeat Extended Curettage is not possible‚ one can always do a Wide Excision and reconstruct with suitable options like tumor endoprosthesis‚ arthrodesis‚ etc.

If the recurrent disease in a treated case of benign bone tumor is detected in time, it is often possible to do an Extended Curettage again and deal with the problem. The vital thing about recurrence of a benign bone tumor is that‚ it rarely ever poses any risk to the life or limb of the patient; unless the recurrence is neglected and is allowed to grow and become huge, or when the recurrence is in diseases occurring in regions which are difficult to treat surgically‚ like in the sacrum‚ spine‚ etc. This is one of the reasons why Extended Curettage is recommended in benign tumors of the bone. However‚ if repeat Extended Curettage is not possible‚ one can always do a Wide Excision and reconstruct with suitable options like tumor endoprosthesis‚ arthrodesis‚ etc.

Regular long-term follow-up after the treatment is not necessary in all benign bone tumors. However, there are certain types of tumors for whicha regular follow-up is mandatory, e.g. in cases of benign aggressive bone tumors like GCT of bone‚ ABC‚ etc. These tumors have a significant risk of local recurrence despite adequate treatment. It is necessary to detect any recurrence of the tumor early‚ as it can be treated effectively when it is small, with minimal disturbance of the surrounding normal tissues/structures. The need for follow-up and its regularity is best advised by your treating doctor.

The following is a list of some of the benign tumors of bone: