Introduction
Tumors in the hand and upper extremity are often seen. In most cases, they are benign lesions, although some of these can be locally aggressive. Much more rarely, these tumors are primary or metastatic malignant lesions. The hand surgeon must know how to deal with the latter and must be aware that an inappropriate first operation can compromise prognosis. Malignant tumors, in particular, can be underestimated because of their rarity and their nonspecific symptoms and may escape early diagnosis.
Surgical treatment should be planned only after having carried out an accurate preoperative assessment of the suspected tumor. Inadequate initial procedures may require a more extensive secondary resection because of seeding to previously uninvolved surrounding tissues. This may compromise the feasibility of a functional reconstruction or even lead to amputation of the affected part. ,
Clinical diagnosis
Clinical presentation
Tumors of the hand and upper limb can arise from any of the tissues. The symptomatology is mostly nonspecific. Usually, they present only as a mass, sometimes as an occasional finding, and are only easy to palpate if superficial. There are no other typical symptoms. Pain is not necessarily present and is not a sign of increased aggressiveness or malignancy. On the other hand, because of their localization or histopathological characteristics, some lesions may have typical symptoms (e.g., osteoid osteomas and glomus tumors).
Clinical examination and diagnosis
Objective examination evaluates the characteristics of the mass by palpation, checking whether it is soft or hard, mobile or adherent to the deep planes or to the skin, and whether it interferes with joint motion or tendon gliding. There may be symptoms of nerve involvement, either sensory or motor, or local vascular changes. Transillumination may distinguish whether a superficial tumor is opaque or transparent.
Imaging investigation is carried out to try to identify the lesion and its margins. Ultrasound and radiographs are used initially. With soft tissue tumors, ultrasound will help identify the characteristics of the mass and its structure, whether cystic or solid, whether the tumor margins are well or poorly differentiated, and whether there are signs of compression, reactive edema, or evidence of tumor infiltration of the neighboring structures. Doppler ultrasound will identify increase or atypia of the vascular network.
Plain radiographs show the volume, shape, and morphology of bone tumors and the characteristics of the margins relative to the surrounding normal bone. They are also useful in demonstrating radio-opaque inclusions in soft tissue tumors and reactive signs of the underlying bone, such as scalloping or osteolysis. MRI and, in some instances, CT is used to examine lesions in more detail. The radiologist should be involved in team discussions to help with the direction of his or her examinations and obtain the data necessary for future management. MRI is mandatory when planning surgery for malignant lesions in order to better define the dimensions and contour of the tumor mass and, in some cases, to get clues as to the histology. When multiple, or metastatic, lesions are suspected, additional examinations of the lymph nodes, lung parenchyma, and skeleton will be necessary. These may include further studies of distant anatomical areas or more specific examinations, such as bone or positron emission tomography (PET) scans, arteriography, or MRI angiography.
The biopsy may be incisional (diagnostic) or excisional (biopsy-excision). In an excisional biopsy, the mass is fully removed, taking care not to interrupt its margin, and sent for histopathological study. This procedure is justified only in a lesion presumed to be benign or in the case of nodules too small to undergo incisional biopsy. Except for these, and whenever malignancy is suspected, a diagnostic, incisional biopsy should be performed. This involves taking a small fragment of the pathological tissue. The sample must be harvested in the central portion of the lesion. Bleeding must be limited, and contamination of the tissue surrounding the sample must be avoided. It is crucial that the skin incision is exactly over the sampling site, straight and not zigzagged or curved, such that the biopsy track and the skin scar may be included in the subsequent radical resection of the tumor mass , , ( Fig. 34.1a, b ) ( Box 34.1 ).
- 1.
Perform excisional biopsy (i.e., total ablation of the suspected neoformation) only for masses too small to permit an incisional biopsy.
- 2.
Always prefer incisional biopsy (i.e., harvesting a small tissue sample from the mass) when the mass is large enough to allow sampling from the core of the lesion without disrupting the surrounding pathologic tissue.
- 3.
Perform the incisional biopsy observing strict rules:
- a.
no local anesthesia (do not infiltrate the lesion or immediately perilesional tissues to avoid contamination).
- b.
do not compress the lesion during exsanguination before inflating the tourniquet.
- c.
use a straight incision made in the center of the mass and on the longitudinal axis of the limb.
- d.
limit incision to the strict necessary for harvesting an adequate sample.
- e.
limit elevating the skin margins to the strict necessary for harvesting an adequate tissue sample.
- f.
avoid unnecessary direct contact with uninvolved tendons or neurovascular bundles.
- g.
avoid perilesional hematoma with accurate hemostasis.
- h.
in the case of needle biopsy, observe the same oncologic rules, keeping in mind that the biopsy tract, whether obtained by incision or needle, should always be included in the subsequent tumor excision.
- a.
Surgical resection
Benign tumors only need local excision of the lesions. For malignant or marginally malignant tumors, wide resection is necessary. Microsurgical techniques have increased the reconstructive possibilities after wide oncological resections of aggressive tumors of bone and soft tissues. The resection is defined as “wide” when the tumor is removed en bloc, surrounded by an uninterrupted margin of surrounding tissue, not infiltrated by neoplastic cells. , , , One of the key concepts on which modern tumor surgery is based is that a wide margin tumor resection is equivalent to amputation in terms of oncological prognosis. In the past, amputation was often the only possible treatment of malignant tumors because of a lack of a subsequent means of anatomical reconstruction and functional recovery of the limb. At present, free microvascular flaps, vascularized bone transfers, and the association of these with established tendon, nerve, and vascular repair techniques have become essential tools to performing effective reparative procedures in tumor surgery.
Benign tumors (Andrzej Zyluk)
Benign tumors of the upper limb are frequently seen. The hand is a complex structure, composed of several tissues, such as skin, fat, tendon, tendon sheath, muscle, nerve, bone, cartilage, etc, each of which can be the origin of a tumor. , The most common tumors seen in the upper extremity are listed in Table 34.1 . They are grouped according to the tissue of origin. The reported incidence of particular types of tumors in the hand varies, but giant cell tumors of the tendon sheath and lipomas are those most frequently encountered. ,
| Origin | Tumors |
|---|---|
| Skin |
|
| Tendon Sheath |
|
| Fat |
|
| Blood vessels |
|
| Nerves |
|
| Muscles |
|
| Fibrous tissue | Fibroma |
| Skeleton |
|
Benign soft-tissue tumors
Ganglion cysts.
Ganglion cysts are the most commonly seen soft tissue tumors in the hand, which present as a smooth, round, soft mass often in the dorsal of the hand or wrist. This is a slow-growing tumor, and it may not affect hand function at all for years, without pain or having only minor dull pain. Palpation of the tumor usually elicits very mild pain.
The cysts can rupture after being pressed or squeezed, which is a treatment option. The cyst can be surgically excised through an incision directly over the mass at any time when the patient wishes, but recurrence after months or years is common. The cyst capsule should be excised as thoroughly as possible. However, the cyst can be deep sometimes, penetrating to ligaments of the hand or carpal bones, in which the surgeons can excise the cyst superficial to the carpal bones without interfering carpal bone or ligaments; because this tumor is benign, partial excision is acceptable.
Giant-cell tumors of the tendon sheath.
Incidence: Excluding ganglion cysts, these are the most common tumor seen in the upper limb, with an incidence of approximately 2% to 5% of all benign tumors in these limbs. They are believed to originate from the synovial tissue of the tendon sheath, although they can be present on the palmar or dorsal aspects of the finger, and perhaps more commonly on the dorsum of the finger where there is no tendon sheath ( Fig. 34.2 ). The favored hypothesis as to their pathogenesis is that they are a reactive or regenerative hyperplasia associated with an inflammatory process.
Presentation.
These lesions are seen in patients in middle age and are more common in women than men. They usually present as a slowly growing subcutaneous mass, localized mostly in the digits, adjacent to the interphalangeal joints. They are slightly hard, immobile, and often granular to palpation of the overlying skin ( Fig. 34.2 ) ( Box 34.2 ). In most cases, they are asymptomatic, but they can cause mild pain and discomfort in some patients and may interfere with hand function. Diagnosis is essentially clinical, but ultrasound and x-ray are frequently performed.
- 1.
Can be present on the palmar or dorsal aspects of the finger, and perhaps more commonly on the dorsum of the finger where there is no tendon sheath.
- 2.
A slowly growing subcutaneous mass, localized mostly in the digits; slightly hard, immobile, and often granular to palpation of the overlying skin.
- 3.
In most cases, they are asymptomatic, but they can cause mild pain and discomfort.
- 4.
Treatment is local excision. These tumors are poorly encapsulated and weave in around the tendons and nerves and sometimes push into bones and joints, making complete excision often difficult. Great care is required in their removal.
- 5.
If the distal ends of the pseudopods are not entirely removed, slow recurrence is likely.
Histology.
Histologically, giant cell tumors are composed of multinucleated giant cells, histiocytes, fibrotic material, xanthine cells, and deposits of hemosiderin. The latter can sometime stain the tumor yellow, which is seen after exposing the tumor ( Fig. 34.3 ). The structure of these lesions is a mixture of inflammatory and neoplastic cells. Neoplastic cells compose from 2% to 17% of the tumor mass and probably produce macrophage colony stimulating factor 1 (CSF1), which activates proliferation of monocytes, macrophages, and related cells.
Treatment.
Treatment is local excision. These tumors are poorly encapsulated and, as they age, form pseudopods that extend from the main body of the tumor to weave in between and around the tendons and nerves and also sometimes push into bones and joints, making complete excision often difficult ( Box 34.2 ). If the distal ends of the pseudopods are not entirely removed, then recurrence, albeit very slowly, is likely. Therefore great care is required in their removal. Fortunately, the yellow-brown color of the tumor tissue helps in this process ( Fig. 34.2 ).
The recurrence rate reported in the literature is high (a mean of 15%, range 4%–40%) and is caused mostly by incomplete excision of the tumor for the above reason. , Factors that increase the risk of recurrence include (1) incomplete excision of the lesion, (2) having residual satellite nodules, (3) involvement of the joint capsule, extensor tendon, and flexor tendon, (4) having pressure erosion of the phalangeal cortex, and (5) the tumor involving the interphalangeal joints or the neurovascular bundle of the digit.
Lipomas.
These benign neoplasms originate from fat tissue and are composed primarily of mature adipocytes. They have an incidence in the upper limb of about 1% to 3.8% of all benign tumors. , They may appear in any age, but most develop in the fourth to fifth decade of life, with a similar incidence in men and women. , Lipomas are common over the whole body, but also in the upper limb, in obese individuals, with abundant subcutaneous tissue. They are usually solitary but may be numerous in any single individual. Usually, multiple lipomas are painless, but they can be painful in Dercum’s disease. Lipomas of diameter >5 cm are called “giant lipomas.” The risk of malignant transformation is low, but it increases with the size of the tumor, for which reason MRI investigation of very large lipomas is useful to detect malignant change in their deeper parts. These lesions present as a soft, mobile, non-tender mass, mostly localized superficially under the skin. They mostly continue to grow slowly in the subcutaneous plane, usually taking up a lobulated shape as they grow and “squeeze” between the fibrous strands tethering the skin to the deeper tissues. In the hand, with growth, they often weave between the various structures of the palm and first web space. Lipomas located close to nerves may present with motor or sensory disturbances, as a result of pressure on the nerves. Occasionally, they develop at a deeper level, below the fascia or in the muscles, and within major nerves, when MRI is indicated.
Small and numerous tumors can be observed and only removed when growing and getting bigger. Surgical resection is the treatment of choice for lipomas as they grow larger, and small to medium-sized, well-encapsulated tumors can be shelled out in toto relatively easily. However, as the lipoma grows, the capsule becomes weaker and less obvious. Thus the difficulties in removing the lobules of the tumor intact from between the fibers of the subcutaneous tissue, and the difficulty distinguishing between poorly contained lipoma and the surrounding normal fat, can make certainty of total excision very difficult. For this reason, and given the rarity of malignant change in these lesions, many surgeons accept partial removal by using liposuction to treat these tumors when presenting more proximally on the limbs and trunk, particularly as they frequently present as a cosmetic problem. This means of treatment also avoids large scars where stretching and hypertrophy/keloiding are possibilities. However, the abundance of vital structures that might be damaged by such a blind procedure precludes the use of liposuction when lipomas arise in the hand.
Resection of lipomas located close to the nerves may be difficult and may cause transient nerve dysfunction due to neuropraxia. These symptoms can persist for as long as one year after operation in some patients, but, providing the nerve was not damaged, they eventually disappear. Intraneural lipomas are often so diffuse that complete excision is impossible, and any symptomatic benefit is probably by decompression of the nerve sheath. The recurrence rate after complete excision is less than 2%, but this probably reflects the relative incidence of the smaller tumors presenting subcutaneously. ,
Hemangioma and vascular malformation.
Tumors of vascular origin are relatively common in the upper extremity, particularly in children. They can be divided into two groups: vascular-derived neoplasms and vascular malformations. Hemangiomas constitute the largest group of benign vascular neoplasms and are seen predominantly in children. There are several syndromes of which hemangiomas are one component ( Table 34.2 ). Vascular malformations are considered disturbances of the morphogenesis and are composed of dysplastic vessels. ,
|
Infantile capillary hemangiomas are the most common benign tumor seen in children, accounting for 65% of all childhood tumors. , About 30% of the lesions are present at birth, and the remainder are apparent by the end of the first year of age. They have a characteristic three-phase evolution: (1) a phase of rapid growth, (2) followed by a static period, and then (3) a slow involution. They present initially as flat, reddish spots that grow to a very variable degree. Treatment is primarily observational as they tend to involute spontaneously, and 50% disappear by the end of the fifth and 70% by the end of the seventh year of age. Symptomatic, or persistent, lesions, mostly obstructing vision or causing bleeding in the nappy area, but rarely in the upper limb, may require active management, which is mostly nonsurgical, such as intralesional steroid injection, intralesional sclerosing agents, pulsed dye laser therapy, and bleomycin. Surgical treatment is indicated when the hemangioma is refractory to these first-line treatments. The diagnosis is clinical, and they do not require investigation unless surgery is being considered, when ultrasound and Doppler-ultrasound may help in delineating the deep margin of the tumor. After complete involution, infantile hemangiomas do not recur. , Involution can leave redundant and loose, wrinkled skin, requiring surgery to remove this excess.
This group of tumors also includes port wine stains and venous lake hemangiomas. These are mostly not a problem of the upper limb likely to require the treatment of hand surgeons and are not discussed further.
Vascular malformations are congenital lesions arising mostly in the head and neck but also occurring elsewhere in the body, including the upper limb. They are due to errors of vascular development that may be present at birth but may only become apparent later in life. Over the years, they may grow larger and become symptomatic. As a consequence, they may present in children or at an older age, generally presenting when they become troublesome. They are a complex group of pathologies with differing combinations of arterial, venous, capillary, and lymphatic components, making for very varied presentation and clinical problems: they can be harmless and minor or very serious, sometimes even life-threatening. They are classified according to the predominant vessel type, but frequently they contain combinations of different vessels. Because of their varied clinical presentations and the different treatments necessary for individual malformations, they have been repeatedly reclassified over recent years, and management is by multidisciplinary teams.
They may present with a grossly abnormal, swollen, and red-purple discolored and pulsatile area of the hand or upper limb that is usually symptomatic, causing pain, paraesthesia, and a feeling of heat. Gigantism of the affected part is common with larger lesions. However, presentation depends on the malformation type, its location and size, and its relation to other anatomical structures. Other symptoms such as skin breakdown, bleeding, vessel thrombosis, and functional impairment may predominate. MRI and MR-angiography are necessary to delineate their extent, mostly because of the requirements of further treatment.
Although small lesions can be resected as a whole, large malformations are usually treated by endovascular interventions, such as embolization, sclerotherapy, and thermal ablation, as the primary therapeutic modality rather than surgery, although secondary surgery may be used after shrinking the malformation. Hand surgeons are commonly the first place of referral of those involving the upper limb and hand. Thereafter, their involvement may be limited. However, interventional radiologists are often reluctant to embolize hand malformations for fear of distal ischemia, and subsequent necrosis and hand surgery alone may be necessary. Excision, either in toto or, more often, partially is often challenging and is often aimed at symptomatic control rather than cure. Pain control may be better achieved by other means, but skin breakdown over the lesion and digital gigantism may necessitate a surgical approach. Where confined to the digits, ray amputation and appropriate reconstruction may be a pragmatic solution. Irradiation has also been used in large lesions that did not respond to other treatments but can cause severe fibrotic reaction in the hand with significant secondary dysfunction. There is no precise data about recurrence rate after treatment of these lesions. , Please also refer to the chapter of vascular disorders for surgical methods.
Nerve tumors: Schwannoma and neurofibroma.
Nerve tumors are relatively uncommon in the upper limb, constituting about 2.5% of benign soft tissue tumors. , , There are two types of these lesions: schwannomas and neurofibromas. Both types occur with a similar frequency and involve both sexes with a similar incidence. Both have malignant variants. ,
Schwannoma.
Schwannoma (also known as neurilemmoma) is a benign tumor that originates from the Schwann cells of the nerve sheath. In most cases, the tumor presents as a single mass. If there are numerous tumors, they are part of neurofibromatosis type 2 syndrome. These tumors are usually seen in the 30 to 60 years age group. Most frequently, they are found in the forearm, involving the median, ulnar, or radial nerve, although tumors arising from small nerve branches do occur at the metacarpal and digital level. The tumors grow slowly and push nerve fibers aside. They occur most often as a solitary tumor but, on occasion, as multiple lesions. Two histological types are distinguished: Antoni A and Antoni B. Malignant schwannomas are very rare.
Presentation.
The tumor commonly presents as a single, painless, and slowly growing mass localized subcutaneously ( Box 34.3 ). By contrast, larger tumors sometimes cause pain or paraesthesia and exhibit a positive Tinel sign. Ultrasound and MRI are useful for clinical diagnosis of these lesions in the forearm.
Schwannoma versus neurofibroma
- 1.
Schwannoma originates from Schwann cells, but neurofibroma is composed of cells with features of a mixture of Schwann cells, perineurial cells, and fibroblasts. Both are tumors of nerve sheath.
- 2.
Both tumors may present as a lump in the nerve trunks, often painless or having mild pain, but Tinel sign is positive and motor or sensory deficits present in both tumors.
- 3.
Ultrasound and MRI provide information of tumor’s location, size and the involved nerve, but cannot differentiate two tumors.
- 4.
Schwannomas can be shelled from the nerve trunk, but neurofibroma need resection of a segment of nerves, followed by nerve grafting, which often causes motor or sensory deficits.
- 5.
During surgery, a longitudinal incision of the nerve and trying to shell the tumor may help know whether it is a Schwannoma or neurofibroma. If not being able to shell the tumor, neurofibroma is likely, then resection and nerve repair/grafting is needed.
Glomus tumor
- 1.
Arising from the glomus body. Mainly found in fingertip, toe, sometimes under nails.
- 2.
A local dark-red or purple nodule under skin or nail. Pain and tenderness, aggravated when exposed to cold. Pinpoint pain, ie, pressure over the site produces remarkable pain. These signs are unique and lead to clinical diagnosis.
- 3.
Bony erosion can be found in plain radiograph sometimes.
- 4.
Local resection of the nodule lead to immediate pain relief.
Treatment.
Surgery is the treatment of choice and includes dissection and excision of the tumor from the nerve ( Fig. 34.4 ). Schwannomas can be shelled from the nerve trunk under local or regional anesthetic ( Box 34.3 ). In excising schwannomas, a longitudinal incision in the nerve trunk at the site of the tumor is made to avoid cutting any nerve fibers in the epineurium expanded by the tumor. The tumor usually has a well-developed capsule that allows enucleation in toto, mostly without damaging nerve fibers ( Fig. 34.4 ), and recurrence after complete enucleation is rare. , However, in longstanding lesions, the nerve fibers may be tightly stretched over the mass, and tumor removal may be difficult without damage to some of these fibers, trapped as they are between the tumor capsule and the outer sheath of the nerve. Some may be divided unintentionally by the initial longitudinal incision of the nerve sheath and others during the process of enucleating the tumor. Recent writing has suggested the tumor may actually infiltrate the nerve fibres.
Complications after surgery cannot be avoided entirely, including impaired sensation and motor deficit. The risk of significant complications has been reported to be greater after operation on motor nerves, such as the posterior interosseus nerve. More proximal upper limb schwannomas, as well as often being a greater surgical challenge, have a higher risk of malignant change.
Neurofibroma.
A neurofibroma is less common, which is also a benign tumor of the nerve sheath. Neurofibroma is composed of cells with features of a mixture of Schwann cells, perineurial cells, and fibroblasts ( Box 34.3 ). Sometimes, it arises from several nerve bundles. In 90% of cases, they are found as a solitary tumor. These tumors arise without known reasons. Commonly cutaneous and subcutaneous neurofibromas either present as pink or skin-colored skin nodules or as small, soft, asymptomatic “lumps,” typically of the forearm and often in people ages 20 to 40 years. These may be larger in size and are usually symptomatic, causing nerve symptoms such as pain, paraesthesia, and paresis of muscles. The remaining 10% of neurofibromas are found in persons with the autosomal-dominant genetically inherited disease, neurofibromatosis type 1. These families develop skin tumors, peripheral nerve sheath tumors, and hyperpigmented café-au-lait spots. Where this syndrome is suspected, family screening is necessary.
Presentation.
A neurofibroma presents as a soft bump on or under the skin. Neurofibroma symptoms are often mild or absent. If the tumor presses against nerves or grows within them, the patient may experience pain or numbness in the affected area. Clinical presentation of a schwannoma is similar. As the disease progresses, the patients with either tumor have motor or sensory disturbance of affected nerves, with mild pain, local mass, and Tinal sign over the tumor. Functional disturbance of the nerves is partial but persistent. The mass is typically round and firm. Clinical diagnosis is made based on the presentations, together with ultrasound or MRI if necessary.
Treatment.
Once diagnosed, most neurofibromas can be excised with nerve grafting. Unlike schwannomas, these tumors cannot be shelled out of the nerve with little damage, and complete removal may require resection of a section of nerve and nerve grafting, or only partial removal ( Box 34.3 ).
For this reason of the tumor not being removed entirely and the possibility of such a tumor being malignant, even where schwannoma or neurofibroma is suspected clinically and from imaging, patients should be warned that exploration of a limb nerve tumor may not be definitive at a single operation but that the first exploration may follow the stages: (1) longitudinal nerve incision to determine whether the tumor is a schwannoma or otherwise; (2) if otherwise, incisional biopsy of the tumor rather than removal; (3) closure of the wound; (4) discussion of the histological diagnosis with the patient before; (5) progressing further to definitive surgery suitable to the pathology. Recurrences are likely after conservative surgery and may force more radical excision, followed by nerve repair. ,
Glomus tumors.
Incidence.
This is a benign hamartoma arising from a neuromyoarterial structure called a glomus body, which controls blood pressure and temperature by regulating blood flow in skin. This tumor accounts for 1% to 4.5% of tumors in the hand. This lesion can be located anywhere, but the subungual region of the distal phalanx is the commonest site of this tumor.
Presentation.
Clinically, the lesion presents with pain and the painful site, often a fingernail, can be located with pinpoint accuracy by the patient. The pain and tenderness are typically increased by exposure to the cold. A localized dark red, or purplish-red, nodule under the skin, or nail, may be visible when the tumor is relatively large and pressure over it is exquisitely painful. X-ray may show scalloping of the underlying distal phalanx ( Fig. 34.5 ). There are two different morphological forms of these lesions: a beige type and a red, blue, or purple-colored type; the former is more difficult to completely excise.
Diagnosis.
Mostly, a diagnosis based on the unique symptoms (particularly, a localized painful site, pinpoint tenderness, with or without a subcutaneous colored nodule) can be made quickly ( Box 34.3 ). Plain radiographs are always taken to observe bony erosion, which is seen in some cases. When the clinical diagnosis is unclear or the tumor recurs after surgery, ultrasound or MRI can help make a definitive diagnosis.
Treatment.
Treatment is almost exclusively surgical and consists in excision or enucleation of the lesion ( Fig. 34.5 ). Some have a well-defined capsule that facilitates removal in total, but this is not always present. The only curative procedure is complete surgical removal of the tumor ( Box 34.3 ). After the operation, the patient feels almost immediate relief from severe pain. The recurrence rate reported in the literature is very variable, ranging from 4% to 50%. , The most common cause of early recurrence is thought to be a result of incomplete excision of the tumor. A second tumor, overlooked at the primary surgery, is another cause. Glomus tumors may be multiple at presentation. Late recurrence is attributed to incomplete removal or development of a new lesion near the excision site.
Benign bone tumors
Enchondroma.
Incidence.
These are the most common benign tumors found in the bones of the upper limb. This tumor is a benign cartilage tumor that occurs in the medullary cavity of bones, often in the hands and feet. Although because of their localization within bone, they are considered to be tumors of bone, these tumors are cartilaginous neoplasm in the medullary bone, presenting as a persistent island of cartilage arising from the bone physis.
Presentation.
Enchondromas are encountered at all ages with the same frequency in both sexes. They most commonly arise in the proximal and middle phalanges of the fingers, particularly the little finger, followed by the metacarpal bones and the distal radius. In children, this disorder may interfere with proper bone development. Enchondromas are predominantly symptomless and the onset of pain may indicate a pathological fracture in most cases. In rare instance, this may indicate malignant transformation to chondrosarcoma. However, transformation of a solitary enchondromatous lesion is rare (less than 1%).
Radiographs.
Most enchondromas more frequently arise in the metaphyseal region, likely due to their origin from the growth plate. In plain radiographs, enchondromas have a variable appearance. Typically they are smaller than 5 cm with intramedullary lytic lesions with non-aggressive features with a sharply defined margin. It should not grow through the cortex, unless a pathological fracture presents ( Box 34.4 ) sharply defined margins. They are usually asymptomatic, being often discovered as an incidental finding on x-ray, but may present as a pathological fracture ( Fig. 34.6 ). By the time they are discovered, they often occupy the entire base of a proximal phalanx, middle phalanx, or metacarpal bone. Although joint motion is usually well-preserved, mild dull pain at the site of the tumor is not uncommon. The diagnosis is made on x-ray.
Enchondroma and bone cysts
- 1.
Enchondroma is a benign tumor, typically asymptomatic, or has very mild pain, often found when pathological fracture occurs. X-rays show an intramedullary lytic lesion with no cortex involvement. No treatment is needed if the patient has no symptoms, but the tumor can be treated with curettage with or without filling the cavity with graft bones.
- 2.
An aneurysmal bone cyst (ABC) is a benign, locally aggressive tumor that occurs in childhood and early adulthood. Radiograph show an eccentric osteolytic lesion. It usually affects the metaphysis of long bones. The diagnosis has to be confirmed by biopsy and histology. Treatment is curettage or en bloc excision, with latter more often recommended.
- 3.
A unicameral bone cyst (UBC) is a benign tumor, primarily occurring in children and adolescents. UBCs are cavities filled with fluid, usually affecting the long bones (often the humerus and the femur). In most cases they are not painful and discovered when an X-ray is obtained for another reason. Pathologic fractures may occur. They do need treatment if small. If it risks pathologic fractures, curettage with bone graft etc. is suggested.
Treatment.
When discovered as an incidental finding, small and asymptomatic lesions can be observed. Routine radiographic follow-up for asymptomatic lesions is usually unnecessary. Surgical excision by curettage of the tumor is the usual treatment for symptomatic patients often after pathologic fractures or to prevent pathologic fractures ( Fig. 34.7 ) ( Box 34.4 ). When necessary, excision of smaller tumors is done by simple curettage without filling the residual cavity. Larger cavities are filled with bone substitutes, such as bone cement, autogenous bones harvested from the distal radius, or allograft. , After surgery, if there is no pathological fracture at the time of diagnosis, immobilization in a dorsal plaster splint or a finger splint for 2 to 3 weeks is usually sufficient. If a pathological fracture is present, internal fixation with K-wires is usually necessary until bone healing is observed ( Fig. 34.7 ). Fixation with a plate is rarely necessary or beneficial. Finger and thumb motion exercises start from the second week after surgery. Recurrence is seen in about 6% of the cases based on a report of 102 enchondromas in 80 patients, treated between 1991 and 2008.
Osteoid osteoma.
Osteoid osteoma is a benign osteoblastic bone tumor that typically occurs in children and younger patients in their second and third decades of life. It predominantly affects men, although patients of all ages and genders can be affected. Osteoid osteomas account for 10% to 12% of benign bone tumors involving the upper limb. Unlike enchondromas, osteoid osteomas occur in various parts of the phalanges, the metacarpals, and the wrist bones. In the wrist, they occur most frequently in the scaphoid. The lesion is usually symptomatic, typically causing pain in the affected part of the hand that is more severe at night. It is often relieved by nonsteroidal antiinflammatory drugs. Distension of the contour of the affected part from swelling of the affected phalanx is the second most common symptom. The diagnosis is made on the symptoms and radiological examination, which reveals a well-defined lytic area with a vascularized central nidus, which is surrounded by sclerosis and cortical thickening. Treatment is commonly by curettage or en bloc excision. Curettage alone is associated with a higher rate of recurrence because of the potential for incomplete excision. Thermo-ablation is an alternative treatment that is increasingly popular. The probe can be introduced precisely into the lesion under 3D navigation, which reduces the risk of iatrogenic thermal injury. Recurrence is uncommon.
Nora’s lesion (bizarre parosteal osteochondromatous proliferation).
This is a very rare, benign, reactive mineralizing mesenchymal tumor. It is usually seen in small bones of the hand in patients in the second and third decades of life with the same frequently in both sexes. It can grow from bone or within the soft tissues of the hand. Typically, it presents as a small, hard, slow-growing and painless nodule that is separate from the overlying skin. Occasionally, growth may be fast, suggesting malignancy. , The lesion has a characteristic three-phase evolution: (1) a parosteal soft-tissue swelling, (2) followed by parosteal, flame-like calcifications, and then (3) a mature osteophytic bony lesion. Diagnosis is sometimes made on the clinical and radiological findings, but it is frequently only made definitively on histological examination. Clinical diagnosis can be difficult because the tumor presentations may be various, according to the stage of development. Thus, it may be confused with other bony lesions such as osteochondroma, periosteal chondroma, and osteo- and chondro-sarcoma. Treatment is commonly by curettage or en bloc excision. The recurrence rate is high, reported as from 29% to 55% within the first 2 years after surgery.
Locally aggressive bone tumors
Giant cell tumors of bone, aneurysmal bone cysts, and unicameral bone cysts are benign but locally aggressive neoplasms that may affect the distal radius and, more rarely, the metacarpals or phalanges. Their more aggressive forms may give rise to metastases and require more radical treatment.
Giant-cell tumor (GCT) of bone.
This is a benign, locally aggressive neoplasm, with a low metastatic potential. It has potential for aggressive behavior and the capacity to metastasize. It is associated with substantial skeletal morbidity. It is usually seen in young patients. Giant cell tumors most often occur in young adults when skeletal bone growth is complete, between 18 and 40 years of life, more frequently women than in men. Histologically, the tumor is rich in osteoclast-like giant cells and contains mononuclear (stromal) cells that express the RANK (receptor activator of nuclear factor kappa-B) ligand, a key mediator of osteoclast activation.
Presentation.
In the upper limb, they are typically found in the distal end of the radius or ulna and in the carpal bones. Clinical presentations include local pain and distension of the contour of the affected part of the extremity (distal forearm, wrist, or digit) because of expansion of the tumor. Lesions localized adjacent to a joint may present with reduction of joint movement.
Radiograph.
Diagnosis is made on a basis of the clinical signs and x-ray, which shows an eccentric, lytic lesion, often with cortical expansion ( Fig. 34.8 ). Early radiographic signs can resemble enchondromas, but the clinical course is different. Consequently, misdiagnosis is unlikely. Unlike enchondroma, presentation with a pathological fracture is very rare. The Campanacci three-grade classification of bony giant-cell tumors is based on the radiological appearance ( Box 34.5 ). Grade 1 lesion (latent) has a well-defined margin and an intact cortex. Grade 2 lesion (active) has a relatively well-defined margin but no radiopaque rim, and the cortex is thinned and moderately expanded. Grade 3 lesion (aggressive) has indistinct borders and cortical destruction.
- 1.
GCT of bone is typically found in the distal end of the radius or ulna and in the carpal bones.
- 2.
Presented with local pain and distension of the contour of the affected part of the extremity.
- 3.
Tumor growth is expansion. Plain radiograph shows eccentric, lytic lesion, often with cortical expansion.
- 4.
The Campanacci classification: Grade 1 lesion (latent) has a well-defined margin and an intact cortex. Grade 2 lesion (active) has a relatively well-defined margin but no radiopaque rim, and the cortex is thinned and moderately expanded. Grade 3 lesion (aggressive) has indistinct borders and cortical destruction.
- 5.
Management is curettage followed by filling the cavity with cancellous bone or bone substitutes. Advanced and recurrent lesions require resection of the affected part of the bone and reconstruction with allograft, autograft, or implant arthroplasty.
- 6.
Primary and recurrent GCT of bone is typically benign. However, rarely, GCT of bone can undergo malignant transformation. The patients with GCT need regular clinical follow-up.
Differential diagnosis.
The differential diagnosis include the brown tumor of hyperparathyroidism, aneurysmal bone cyst, telangiectatic osteosarcoma (a subtype of osteosarcoma characterized by empty or blood-filled cystic spaces separated by septa), and malignant fibrous histiocytoma.
Treatment.
Management of small lesions is similar to that of enchondromas and consists of curettage followed by filling the cavity with cancellous bone or bone substitutes such as bone cement ( Box 34.5 ). There is a high rate of recurrence after most methods of local treatment. Treatment of advanced and recurrent lesions requires resection of the affected part of the bone, followed by reconstruction with fresh-frozen osteoarticular allograft, structural autograft ( Fig. 34.9 ), or implant arthroplasty (e.g., an ulnar head prosthesis). Microsurgical vascularized bone transfers are also currently used to reconstruct major oncological defects in the long bones of the upper extremity, such as after resection of GCT of the distal radius with a free vascularized fibular head graft. In inoperable and recurrent cases with metastases, Denosumab, a monoclonal antibody against RANK ligands, has been successfully tested.
Prognosis.
Giant cell tumors are rarely life-threatening. Primary and recurrent GCT of bone is typically benign. However, rarely, GCT of bone can undergo malignant transformation. Malignancy in GCT of bone may be primary (adjacent to benign giant cell tumor of bone at first diagnosis) or secondary (at the site of previously treated giant cell tumor of bone) with a poor prognosis. Patients with GCT of the bone need regular clinical follow-up.
Aneurysmal bone cyst (ABC).
Primary ABC is a benign, osteolytic, hyperplastic, hyperemic-hemorrhagic lesion reactive to a local alteration of unknown nature and origin. It is rare, accounting for only 1% of bone tumors. In 90% of cases, it involves younger patients, under 20 years old. Its location is usually metaphyseal or metadiaphyseal. From the metaphysis, ABC may involve the epiphysis even in the presence of an open growth plate. On x-ray, in the early phase it appears as an eccentric, or subperiosteal, osteolytic lesion that is well circumscribed ( Box 34.4 ), with no reactive bone or sclerotic margin. The lesion enlarges with marked cortical destruction associated with a periosteal osteogenic reaction. In the late reparative phase, the lesion may progressively ossify, with coarse trabeculation (frosted glass aspect).
The differential diagnosis includes fibrous dysplasia, GCT of bone, simple bone cyst, eosinophilic granuloma, chondromyxoid fibroma, hyperparathyroidism, and lytic osteosarcoma. In differentiating the lesion from GCT of bone, ABC usually involves a younger patient and is located in the metaphysis or diaphysis. As with GCT of bone, treatment consists of curettage or en bloc resection ( Box 34.4 ). Because recurrences are common, en bloc excision is more often recommended.
Unicameral bone cyst (UBC).
This is a benign, single-chambered and fluid-filled, intraosseous cyst that is self-limiting. In the upper limb, it occurs most frequently in the proximal humerus ( Box 34.4 ), and less often in the distal radius and hand. It has a metaphyseal location. It is usually asymptomatic, but pathological fracture through the cyst may occur. It accounts for 3% of primary bone tumors, with 80% of patients being less than 20 years old. On x-ray, it appears as a purely lytic lesion with a well-defined contour ( Fig. 34.10 ). The cortex may be thinned but is never penetrated by the lesion. Periosteal reaction is only observed in the presence of a pathological fracture. The “fallen fragment” sign, such as a pathological fracture in which a small bone fragment “sinks” into the cyst, is seen in 20% of lesions. When present, this sign is almost pathognomonic of a unicameral bone cyst, although there are a few case reports of this sign associated with other cystic bone lesions (e.g., eosinophilic granuloma). In younger patients, this bone cyst appears directly opposed to the growth plate in the metaphysis. It can progress into the diaphysis as the bone grows. Small, asymptomatic lesions do not require any treatment. Larger lesions should be treated because of the risk of pathological fractures. Corticosteroid (methylprednisolone) injected into the cyst may be helpful. Contraindications to steroid treatment include multilocular appearance, larger size, and radiographically active lesions.
