Tumors of the hand and upper extremity can be classified as benign soft tissue tumors; malignant soft tissue tumors (subclassified into cutaneous and noncutaneous malignancies); benign bony tumors; malignant bony tumors; and secondary metastatic tumors. Initial investigation for any mass starts with a complete history and physical exam. Hand and/or wrist X-rays should be obtained in every patient presenting with a mass unless clearly not indicated (e.g., a superficial skin lesion with no aggressive/malignant features). The workup proceeds in an orderly fashion until a diagnosis is obtained. Once a benign diagnosis is secured (by strong clinical suspicion in an experienced hand surgeon, radiographic evidence, or tissue biopsy), further workup is not needed; this may occur at any point in the workup of a mass.
Most hand masses are benign and can be readily diagnosed without advanced imaging or tissue biopsy. When necessary, additional workup may include baseline laboratory studies, CT and/or MRI of the involved region, and a bone scan or positron emission tomography (PET) scan. Staging of a malignant tumor may occur before biopsy if a malignancy is strongly suspected, or it may occur after formal biopsy. Staging includes a chest X-ray and CT with intravenous contrast of the chest, abdomen, and pelvis to detect possible metastasis. Biopsy of the mass is always the last step of a workup and should occur only after all other available information has been gathered. Any mass that is over 5 cm in size, is rapidly increasing in size (as judged by an experienced surgeon or oncologist), is symptomatic or painful, or has an aggressive clinical or radiographic appearance warrants workup and biopsy to rule out malignancy.
CT scans are useful for detecting bony tumor extension across planes and identifying tumors of small bones, such as the carpal bones. MRI is useful for evaluating soft tissue tumor involvement (e.g., which muscle compartments are involved) as well as intramedullary lesions. Most soft tissue tumors will appear dark on T1-weighted images and bright on T2-weighted images. Hematomas, hemangiomas, lipomas, liposarcomas, and adipose tissue will appear bright on T1-weighted images and dark on T2-weighted images. Scintigraphy uses methylene diphosphonate attached to technetium-99m. This complex will attach to hydroxyapatite. Immediate uptake is seen in areas of increased vascularity, such as infection, trauma, and neoplasia. Increased uptake 2 to 3 hours later is seen in “pooled” areas where new bone formation has occurred. This modality is useful for detecting areas of tumor invasion or metastases not otherwise seen on prior CT, MRI, or radiographs.
Biopsy is reserved for masses that cannot be diagnosed as benign based on prior clinical and radiographic exams. Needle biopsy is not reliable for primary diagnosis, but it can be useful for recurrent or metastatic disease. Open excisional (if mass is <5 cm in size) or incisional (if mass is >5 cm in size) biopsy is the most common biopsy method. Proper surgical oncologic technique is strictly adhered to in order to prevent tumor spread into uninvolved tissues or compartments. This includes making all incisions longitudinally using sharp dissection and meticulous hemostasis; carrying the incision directly down to the tumor with no development of tissue planes (i.e., making a straight-line path from skin to tumor); incising through the fewest number of muscle compartments; and avoiding critical neurovascular structures. The CT or MRI images will help determine the best surgical approach for biopsy or resection in order to avoid uninvolved compartments and critical structures.61
Benign Soft Tissue Tumors
This is the most common soft tissue tumor of the hand and wrist, comprising 50% to 70% of all soft tissue tumors in this region. They can occur at any age but are most common in the second to fourth decades with a slight predilection toward females. Patients may report a slow-growing soft mass that may fluctuate in size and can sometimes be associated with mild pain. Compressive neuropathies may be seen if they occur in Guyon’s canal or the carpal tunnel, but are uncommon. There are no reports of malignant degeneration.62 History and physical exam are usually sufficient to establish a diagnosis. Occurrence by location is as follows: 60% to 70% occur on the dorsal wrist between the third and fourth extensor compartments and are connected by a stalk to the scapholunate ligament (Fig. 44-24); 18% to 20% occur on the volar wrist; and 10% to 12% occur in the digits as volar retinacular or flexor tendon sheath cysts. The cyst transilluminates. There is always a stalk that communicates with the underlying joint or tendon sheath. The cyst wall is composed of compressed collagen fibers with no epithelial or synovial cells present. Clear viscous mucin fills the cyst and is composed of glucosamine, albumin, globulin, and hyaluronic acid. The etiology is unclear. The most accepted theory currently is Angelides’ who proposed that repeated stress of a joint, ligament, or tendon sheath causes an increase of mucin-producing cells and subsequent mucin production. The increased mucin production dissects superficially and coalesces into a cyst. The successful treatment of dorsal ganglion cysts by excising only the stalk supports this theory.63
Dorsal wrist ganglion cyst. These typically occur between the third and fourth dorsal extensor compartments and have a stalk connecting the base of the cyst to the scapholunate ligament.
Treatment consists of observation if asymptomatic. If symptoms exist or the patient desires removal for cosmetic appearance, aspiration of the cyst may be performed with a successful cure rate ranging from 15% to 89%. The benefit of injected steroids is inconclusive. Aspiration of a volar wrist ganglion cyst can be dangerous due to the potential of injuring neurovascular structures. Open excision and arthroscopic excision of the cyst stalk are surgical options for cysts that are not amendable to aspiration. Recurrence rate after surgical excision ranges from 4% to 40%.62
A mucous cyst is a ganglion cyst of the DIP joint. They occur most commonly in the fifth to seventh decades, and the underlying cause is associated osteoarthritis of the DIP joint. They are slow growing and usually occur on one side of the terminal extensor tendon between the DIP joint and the eponychium. The earliest clinical sign is often longitudinal grooving of the involved nail plate followed by a small enlarging mass and then attenuation of overlying skin. X-rays will show signs of osteoarthritis within the DIP joint. Heberden nodes (osteophytes within the DIP joint) are often seen on X-ray.
Possible treatment includes observation, aspiration, or excision. If the cyst is not draining and the overlying skin is intact, the patient may be offered reassurance. A draining cyst poses risk of DIP joint infection due to the tract communicating with the DIP joint and should be excised. If the cyst is symptomatic, painful, or the patient desires removal for cosmetic purposes, excision should be performed. Any osteophytes in the DIP joint must be removed to reduce recurrence. Aspiration is an option for treatment, but this poses the risk of DIP joint infection through seeding of bacteria into the joint or by the development of a draining sinus tract. It is generally not performed.
Giant Cell Tumor of the Tendon Sheath
Also known as a fibrohistocytoma, fibrous xanthoma, localized nodular synovitis, or pigmented villonodular synovitis, this is the second most common soft tissue mass of the hand and wrist. It is a benign lesion with no clear pathogenesis. The tumor is a growth of polyclonal cells with no risk of metastases. Despite the similarity in name, it is not histopathologically related to giant cell tumor of the bone.64
Giant cell tumor of the tendon sheath occurs as a firm slow-growing painless mass over months to years and will often feel bumpy or nodular, which is a distinguishing characteristic helpful for diagnosis. It has a predilection for occurring in close proximity to joints along flexor surfaces of the wrist, hands, and digits (especially the PIP joints of the radial digits) and occurs most commonly between the second and fifth decades (Fig. 44-25A). These tumors do not transilluminate. Direct extension into joints and ligaments can make complete excision difficult. Gross appearance of the tumor will show a well-circumscribed nodular firm mass with a deep brown color due to the large amount of hemosiderin content, which is easily detected on histologic staining (Fig. 44-25B). Multinucleated giant cells and hemosiderin-laden macrophages are characteristic.64
Giant cell tumor of tendon sheath. A. The mass produces lobulated enlargement of the external finger. B. The excised giant cell tumor has a multilobulated, tan-brown appearance.
This tumor is not visible on radiographs. Approximately 20% will show extrinsic cortical erosion on X-ray. This is a risk factor for recurrence, and removal of the cortical shell should be considered. MRI is useful for delineating involvement with tendons, ligaments, and joints.
The standard treatment is marginal excision. These tumors will often grow next to or around neurovascular bundles, and an Allen’s test should always be performed preoperatively to confirm adequate blood supply by both ulnar and radial arteries as well as dual blood supply to an involved digit via the ulnar and radial proper digital arteries. It is important to completely excise the stalk because this will greatly reduce tumor recurrence even in the setting of residual tumor. If tumor is suspected to have extended into the joint, the joint must be opened and all tumor removed. Despite this being a benign lesion, local recurrence is approximately 30% (range, 5%–50%). Some variants can mimic more aggressive processes, and malignancy must be considered if aggressive features are identified, such as direct bony invasion.64
Lipomas of the hand and wrist may occur in multiple anatomic locations, including subcutaneous tissues; intramuscularly (especially thenar or hypothenar muscles); deep spaces; carpal tunnel or Guyon’s canal; and rarely bone or nerve. They typically present as a painless, slow-growing, soft, and mobile mass over a period of months to years. Painful findings suggest close approximation to a neurovascular structure or, less commonly, a malignant lesion such as liposarcoma. Lipomas do not transilluminate. They resemble mature fat histologically. X-rays typically reveal no abnormality. MRI is the most helpful imaging modality to evaluate a lipoma and will show a bright T1 lesion and dark T2 lesion.65
Asymptomatic lesions with no aggressive findings may be observed. Marginal excision is recommended for symptomatic, painful, or enlarging lipomas or those that cause dysfunction. MRI is recommended for deep lipomas to evaluate proximity or involvement of critical structures, followed by marginal excision if MRI findings are consistent with a lipoma. If MRI findings are not consistent with a lipoma, incisional biopsy is warranted. Recurrence after marginal excision is rare. Malignant degeneration to liposarcoma is exceedingly rare but has been reported.
A schwannoma, also known as a neurilemmoma, is a type of benign peripheral nerve sheath tumor. It is the most common benign peripheral nerve sheath tumor of the upper extremity.66 The majority occur as single solitary masses. Patients with neurofibromatosis type 1 (NF1) or 2 (NF2) may develop multiple schwannomas involving large peripheral nerve trunks or bilateral acoustic schwannomas, respectively. These tumors arise from the Schwann cell and occur most often in the middle decades of life. They grow as painless, slow-growing, firm, round, well-encapsulated masses with a predilection toward flexor surfaces of the forearm and palm (given their presence of large nerves). Schwannomas grow from the peripheral nerve sheath and are usually connected by a pedicled stalk. The tumor is well demarcated and can be readily separated from the nerve fascicles (Fig. 44-26). Unlike neurofibromas, they do not grow within the nerve. Paresthesias or other neurologic findings may occur, but they are usually absent, as is the Tinel’s sign. Findings such as pain, paresthesias, or numbness should raise concern for a tumor causing a compressive neuropathy or a tumor that is malignant.66
Schwannomas grow as a firm, round, well-encapsulated mass within the epineurium of a peripheral nerve. Schwannomas are able to be separated from the nerve fascicles relatively easily because they do not infiltrate between them (unlike neurofibromas).
Histologic exam reveals Antoni type A palisades of spindle cells with large oval nuclei with interlacing fascicles. Less cellular regions appear as Antoni type B areas. Mutations of the schwanomin gene on chromosome 22 are found in 50% of sporadic cases and 100% of acoustic schwannomas in patients with NF2.67
Surgical treatment is reserved for symptomatic tumors and those that require biopsy to rule out a malignant process. An MRI should be obtained prior to surgery to confirm that the tumor is not located within the nerve (i.e., a neurofibroma) and that it is consistent with a schwannoma. Operative treatment involves excisional biopsy. If the tumor is adherent to adjacent soft tissue or not encapsulated, incisional biopsy is performed and excision is delayed pending pathology results. Malignant degeneration is exceedingly rare.66
Malignant Soft Tissue Tumors—Cutaneous
Squamous cell carcinoma (SCC) is the most common primary malignant tumor of the hand, accounting for 75% to 90% of all malignancies of the hand. Eleven percent of all cutaneous SCC occurs in the hand.68 It is the most common malignancy of the nail bed. Risk factors include sun exposure, radiation exposure, chronic ulcers, immunosuppression, xeroderma pigmentosa, and actinic keratosis. Marjolin’s ulcers represent malignant degeneration of old burn or traumatic wounds into an SCC and are a more aggressive type. Transplant patients on immunosuppression have a four-fold increased risk and patients with xeroderma pigmentosa have a 1000-fold increased risk of developing an SCC. They often develop as small, firm nodules or plaques with indistinct margins and surface irregularities ranging from smooth to verruciform or ulcerated (Fig. 44-27). They are locally invasive, with 2% to 5% lymph node involvement. Metastasis rates of up to 20% have been reported in radiation or burn wounds. Standard treatment is excision with 0.5- to 1.0-cm margins. Other treatment options include curettage and electrodessication, cryotherapy, and radiotherapy.68
Squamous cell carcinoma involving the nail fold and nail bed. Note the wart-like and ulcerated appearance.
Basal cell carcinoma (BCC) is the second most common primary malignancy of the hand, accounting for 3% to 12%; 2% to 3% of all BCCs occur on the hand. Risk factors are similar for SCC and include chronic sun exposure, light complexion, immunosuppression, inorganic arsenic exposure, and Gorlin’s syndrome. Presentation includes a small, well-defined nodule with a translucent, pearly border and overlying telangiectasias (Fig. 44-28). Metastasis is very rare. Standard treatment is excision with 5-mm margins. Other treatment options include curettage and electrodessication, cryotherapy, and radiotherapy.68
Basal cell carcinoma of the dorsal hand with surrounding telangiectasia.
Melanoma accounts for approximately 3% of all primary malignant hand tumors.69 Risk factors include sun exposure (especially blistering sunburns as a child), dysplastic nevi, light complexion, family history of melanoma, and congenital nevi. Pigmented lesions with irregular borders, color changes, increase in growth, or change in shape are suggestive of melanoma. Breslow thickness is the most important factor in predicting survival for a primary melanoma. Surgical treatment includes excision with 1-cm margins for lesions up to 1 mm in thickness and 2-cm margins for lesions over 1 mm in thickness. Sentinel lymph node biopsy is done for lesions over 1 mm in thickness or for any lesion that is ulcerated and over 0.76 mm in thickness.70 Any clinically palpable lymph node requires a formal lymph node dissection of the involved basin, as do sentinel lymph nodes positive for melanoma. Lymph node dissection has not been shown to offer any survival benefit, but the information gained from sentinel lymph node biopsy (or lymph node dissection) does offer valuable staging information that is important for prognosis. Subungual melanomas are treated with DIP amputation, with 5-year survival reported at 66%.71
Malignant Soft Tissue Tumors—Noncutaneous
Primary soft tissue sarcomas of the upper extremity are very rare, and most hand surgeons will only see several throughout their entire career. Only 14% of all soft tissue sarcomas occur in the entire upper extremity. Statistical inference is limited due to the rare occurrence of these tumors, but mortality rate is very high despite the aggressive treatments. Fewer than 5% of soft tissue sarcomas of the upper extremity will develop lymph node metastasis. Cutaneous malignancies must be considered in the differential diagnosis for any patient with palpable lymph nodes in the setting of any upper extremity mass. Any lesion of the upper extremity that is over 5 cm in diameter, rapidly enlarges, or is painful should be considered malignant until proven otherwise.72
Treatment for soft tissue sarcomas can range from palliative debulking to attempted curative resection. Many muscles of the upper extremity and their compartments cross joints (e.g., forearm flexors). Any malignancy within a compartment mandates complete resection of that compartment, and therefore, amputations must often be performed at levels much more proximal than the level of the actual tumor. Many soft tissue sarcomas are not responsive to radiation or chemotherapy, and use of these adjuvant treatments must be decided upon after discussion with medical and radiation oncologists in a multidisciplinary team. Several studies have shown higher mortality rates in patients who undergo initial tumor biopsy of sarcomas at institutions from which they do not ultimately receive treatment. These studies recommend biopsy be performed at the institution at which definitive treatment will be provided.73 Institutions best suited for such treatment should have pathologists familiar with soft tissue sarcomas, medical and radiation oncologists, surgical oncologists, and a multidisciplinary tumor board.
An in-depth review of each type of soft tissue sarcoma is beyond the scope of this chapter. Epithelioid sarcoma is the most common primary soft tissue sarcoma of the upper extremity and usually presents as a benign-like slow-growing mass during the third or fourth decades. It has a propensity for the forearm, palm, and digits. Spread to lymph nodes has been reported. It typically spreads along fascial planes.74 Synovial sarcoma is argued by some to be the most common primary soft tissue sarcoma of the hand and wrist, but the paucity of case reports is inconclusive. It is a high-grade malignancy that is painless and slow-growing and usually occurs adjacent to, but not involving, joints. It is most common in the second to fifth decades of life. Tumor size (>5 cm) is positively correlated with mortality. Other sarcomas include malignant fibrous histiocytoma, liposarcoma, fibrosarcoma, dermatofibrosarcoma protuberans, and malignant peripheral nerve sheath tumors, and more information can be found in further selected reading.75 The majority of metastases to the hand involve secondary bone tumors and are discussed later in the section Secondary Metastatic Tumors.
Primary benign bone tumors of the hand and wrist make up a total of 7% of all primary benign bone tumors in the body. Benign tumors of cartilage origin comprise 79% of all primary benign bone tumors of the hand and wrist.76
This is the most common primary benign bone tumor of the hand and wrist and is of cartilage origin. Up to 90% of all bone tumors in the hand and wrist are enchondromas, with 35% to 54% of all enchondromas occurring in the hand and wrist. They are often found incidentally on X-rays taken for other reasons (e.g., hand trauma). They are usually solitary and favor the diaphysis of small tubular bones and are most common in the second and third decades of life. The most common location is in the proximal phalanges, followed by the metacarpals and then middle phalanges. Enchondroma has never been reported in the trapezoid. Presentation is usually asymptomatic, but pain may occur if there is a pathologic fracture or impending fracture. The etiology is believed to be from a fragment of cartilage from the central physis. Histology shows well-differentiated hyaline cartilage with lamellar bone and calcification.76
Two variants of enchondroma include Ollier’s disease (multiple enchondromatosis) and Maffucci’s syndrome (multiple enchondromatosis associated with multiple soft tissue hemangiomas). Malignant transformation is very rare in the solitary form, but there is a 25% incidence by age 40 in Ollier’s patients and a 100% life-time incidence in Maffucci’s patients. When malignant transformation does occur, it is almost uniformly a chondrosarcoma with pain and rapid growth.77
Diagnosis is usually made based on history, physical exam, and X-rays. There is a well-defined, multilobulated central lucency in the metaphysis or diaphysis that can expand causing cortical thinning or, sometimes, thickening (Fig. 44-29A). Further imaging is seldom needed, but a CT would be the study of choice.
Enchondroma. A. X-ray of the phalanx demonstrates a well-defined central lucency. Surrounding cortex may thin or thicken. Thinning of the cortex contributes to risk of pathologic fracture. B. Intraoperative fluoroscopy after curettage of the tumor. A radiopaque ribbon is used to occupy the defect to help ensure that there is no tumor (similarly radiolucent to the defect after curettage) left behind prior to bone grafting.
Observation is indicated for asymptomatic enchondromas with no risk of impending fracture, followed by annual X-rays for 2 years. If a pathologic fracture is found, it is treated with immobilization until fracture union and then surgically treated. If there is any uncertainty as to whether it is an enchondroma, incisional biopsy is indicated and definitive treatment is postponed pending final pathology. Symptomatic lesions and those with impending fracture are treated surgically. Surgical treatment consists of an open incisional biopsy and confirmation by frozen section that it is well-differentiated hyaline cartilage. Curettage and high-speed burring are used to ablate the tumor. Intraoperative fluoroscopy is used to confirm complete ablation (Fig. 44-29B). The defect is then packed with bone graft or bone substitute. Recurrence ranges from 2% to 15%. X-rays should be obtained serially after surgery.76
Periosteal chondromas are benign bone tumors of cartilage origin that arise most commonly within or adjacent to periosteum at the metaphyseal-diaphyseal junction in phalanges. They occur usually in the second or third decade as solitary lesions with pain, swelling, deformity, and possible pathologic fracture. X-rays reveal a subperiosteal lytic, unilobular lesion with erosion into adjacent cortex. There is often a rim of sclerosis. Histologically, they appear as aggressive cartilage with atypia, and it can be difficult to differentiate these from chondrosarcomas.76
Diagnosis involves X-rays with incisional biopsy to confirm the benign diagnosis and avoid unnecessary amputation. Treatment includes en-bloc resection of periosteum and corticocancellous bone. Recurrence is less than 4%.
This is a tumor of bone origin. Approximately 5% to 15% of all osteoid osteomas occur in the hand and wrist and are most often found in the proximal phalanx or carpus. They usually occur in the second or third decade and present with a deep, dull ache that is classically worse at night and relieved by nonsteroidal anti-inflammatory drugs (NSAIDs). X-rays reveal a central lucency that is usually less than 1 cm in diameter surrounded by reactive sclerosis. Bone scan or CT is helpful to secure the diagnosis.78
Treatment consists of NSAID therapy only, and resolution occurs at an average of 33 months. If the patient does not wish to undergo prolonged discomfort with conservative therapy, curettage or percutaneous ablation of the nucleus may be performed.78
Giant cell tumors of bone make up only 5% of all benign bone tumors in the body, and only 12% of these occur in the hand or wrist. Although its name is similar to that of “giant cell tumor of tendon sheath,” they are two separate tumors and do not share the same clinical or histopathologic characteristics. Approximately 2% occur in the hand and 10% occur in the distal radius; those within the distal radius are more aggressive. They usually occur in the fourth decade with pain and swelling and possibly pathologic fracture.79
Giant cell tumor of the bone is unique in that it is benign on histology but does have metastatic potential and can cause death. It should be considered a low-grade malignancy.79 Workup includes a CT of the chest and total-body scintigraphy to evaluate for metastases and multifocal lesions and MRI to evaluate the extent of local tissue involvement. Treatment consists of amputation of involved phalanges or metacarpals and wide excision of entire carpal rows. Local and systemic surveillance must be done for at least 10 years because metastasis has been reported to occur as late as 10 years postoperatively.79
Malignant primary and secondary bone tumors of the hand, like soft tissue malignancies, are exceedingly rare. An in-depth review is beyond the scope of this chapter. The same principles for soft tissue sarcomas of the upper extremity apply here with regard to evaluation, biopsy, and treatment.
Chondrosarcoma comprises 41% of all primary malignant bone tumors of the hand and wrist but only 1.5% of all chondrosarcomas overall. It is most likely to occur from malignant degeneration from a preexisting lesion, with enchondromatosis and osteochondromatosis being the most common. It usually presents as a slow-growing, painless mass in the fourth to sixth decades and can be difficult to differentiate from its benign counterparts. X-ray reveals endosteal erosion, cortical expansion, cortical destruction, and calcification. Metastasis has never been reported for chondrosarcomas of the hand. Chondrosarcomas are not responsive to chemotherapy or radiation.80
Osteosarcoma of the hand is exceedingly rare; only 0.18% of osteosarcomas occur in the hand. It usually presents as a painful swelling with pathologic fracture in the fifth to eighth decades of life. Radiation exposure is believed to be a possible risk factor. X-ray findings vary widely, with 90% of tumors occurring at a metaphyseal location. Findings include an osteoblastic or osteolytic lesion, cortical breakthrough with soft tissue extension, a “sunburst” pattern radially, or periosteal elevation (Codman’s triangle). The presence or absence of metastasis is the most important prognostic factor, with a 5-year survival of 70% in the absence of metastases and a 5-year survival of 10% if present. Preoperative chemotherapy is usually given, but radiation therapy plays no role.81
Secondary Metastatic Tumors
Metastases to the hand or wrist are rare, with only 0.1% of skeletal metastases occurring in the hand. The majority of metastases to the hand are bone lesions, but soft tissue metastases have been reported. The most common primary site is the lung (40%), followed by the kidney (13%) and the breast (11%). Approximately 16% will have no known diagnosis of cancer.82 The most common sites are the distal phalanges, followed by the proximal and middle phalanges, metacarpals, and carpus. Patients will present with pain, swelling, and erythema. Differential diagnosis includes felon, gout, osteomyelitis, trauma, RA, or skin cancer. Treatment of a hand or wrist metastatic lesion must not interfere with treatment of the primary cancer. Treatment is usually palliative (simple excision or amputation). The average life expectancy for these patients is less than 6 months.82