Tumors and Tumorous Conditions of the Hand

Chapter 77 Tumors and Tumorous Conditions of the Hand




Hand masses may result from tumors and tumorous conditions. Although most of these masses are benign, they should be considered potentially problematic and managed with great diligence. Because the hand has limited free space and exquisite sensitivity, small and histologically benign masses can cause pain and significantly impair function. However, most hand neoplasms develop insidiously without significant pain or tenderness (including those that are malignant) and thus cosmetic concerns may be the patient’s only presenting complaint. For this reason abnormal hand and finger growths should not be discharged as routinely benign. Malignant lesions that arise primarily from tissues other than the skin are rare, and our knowledge is derived mainly from small series and case reports. The hand may be the site of distant breast, lung, or kidney adenocarcinoma metastases, most of which occur in the distal phalanges.



Classification


Tumors involving the hand are classified in a manner similar to that for tumors involving the rest of the body. Benign tumors are classified as latent, active, or aggressive, according to their local biological activity (Table 77-1). Benign latent tumors are those in which tumor growth has occurred during childhood or adolescence and has subsequently entered an inactive or healing phase. Solitary and unicameral bone cysts are examples of benign latent tumors. A benign active tumor continues to enlarge and, although it is well encapsulated, may have an irregular or lumpy border. Most benign tumors of the hand fall into this category. A benign aggressive tumor, although nonmetastasizing and innocent appearing on histological sections, is locally destructive and is surrounded by a thin, tenuous capsule that may not contain all the tumor cells. A giant cell tumor of bone often behaves in this aggressive manner. A wide margin often is necessary for complete eradication of benign aggressive tumors.


TABLE 77-1 Classification of Benign Tumors















STAGE TYPE
1 Latent
2 Active
3 Aggressive

Modified from Enneking WE: Musculoskeletal tumor surgery, New York, 1983, Churchill Livingstone.


Malignant tumors are classified as low grade (I), high grade (II), or associated with metastasis (III) (Table 77-2). Most malignant tumors of the hand are low-grade tumors and are classified further, according to the degree of local extension, as either intracompartmental (A) or extracompartmental (B). In the hand, each ray forms a distinct compartment. The individual phalanges are not considered separate compartments, but rather they, along with their corresponding intrinsic muscles, are included in the ray compartment. The ray compartment includes the flexor tendon and sheath of each finger as far proximally as the midpalmar space and the extensor tendon as far as the metacarpophalangeal joint. Each metacarpal is a separate compartment. If a tumor involves the palmar space or the loose areolar tissue on the dorsum of the hand, it is considered extracompartmental because proximal spread is unobstructed. Tumors arising in the digits remain confined to that compartment for long periods and then extend into the palm.


TABLE 77-2 Classification of Malignant Tumors





















STAGE TYPE
IA Low grade, intracompartmental
IB Low grade, extracompartmental
IIA High grade, intracompartmental
IIB High grade, extracompartmental
III Either grade with regional or distant metastasis

Modified from Enneking WF, Spanier SS, Goodman MA: The surgical staging of musculoskeletal sarcoma, Clin Orthop Relat Res 153:106, 1980.




Treatment


Generally, hand tumors are treated surgically. Biopsy rarely is needed in most tumors because complete excision usually is indicated, and the entire tumor is available for microscopic study. Incisional biopsy is advised if a malignant tumor is suspected, or if the morbidity of surgical excision outweighs the morbidity caused by the tumor itself, as may be true in some benign neural tumors. Incisions should be made directly over the mass to be harvested for biopsy and should be oriented so as not to jeopardize hand function or interfere with complete removal of the tumor. The way in which a tumor is removed depends on its location, aggressiveness, potential for metastasizing, and, at times, sensitivity to adjuvant chemotherapy and radiation therapy. The various surgical margins are summarized in Table 77-3.


TABLE 77-3 Classification of Surgical Margins


















TYPE PLANE OF DISSECTION
Intracapsular Piecemeal, debulking, or curettage
Marginal Shell out (en bloc) through pseudocapsule or reactive zone
Wide Intracompartmental (en bloc) with cuff of normal tissue
Radical Extracompartmental (en bloc) with entire compartment

Modified from Enneking WE: Musculoskeletal tumor surgery, New York, 1983, Churchill Livingstone.


Benign soft tissue tumors are treated by excisional biopsy (marginal excision). Benign tumors of bone often are treated by curettage (intracapsular) and, occasionally, bone grafting. Malignant tumors require a wide excision in which a 2-cm tumor-free cuff of tissue is removed with the tumor. Malignant tumors involving the distal phalanx can be treated with a transdiaphyseal amputation through the middle phalanx. Malignant tumors of the middle phalanx can be treated with a transdiaphyseal amputation through the proximal phalanx. If the malignant tumor involves the proximal phalanx, a ray amputation usually is required. Malignant tumors of the metacarpals, especially if large and extracompartmental, often require adjacent amputations to achieve adequate surgical margins. Grade IIB lesions involving the hand may require amputation through the distal third of the forearm at a level just proximal to the musculotendinous junctions. Reconstruction after wide or radical excisions for malignant tumors of the hand should be delayed until tumor-free margins have been documented.



Benign Tumors (Table 77-4)



Lipoma


Although lipomas are more common elsewhere in the body, they also are found in the hand and are common solid cellular hand tumors (Fig. 77-1). These lightly encapsulated tumors are composed of mature fatty tissue in which the central lipid droplet and peripherally located nucleus form the characteristic signet-ring cell. They arise from mesenchymal primordial fatty tissue cells. These tumors can be superficial, arising from the subcutaneous tissues and having the characteristic signs of a soft, fluctuant, bulging mass, or they can occur deep in the palm, arising within the Guyon canal, the carpal tunnel, or the deep palmar space. Usually, a painless mass is present that impairs grasp. Lateral deviation of the fingers also may be present when the tumor is located around the metacarpophalangeal joints.




Median or ulnar nerve compression from these tumors can cause muscular weakness or diminished sensibility. Lipomas project through spaces of least resistance, and those deep palmar space lesions tend to present distally between the fingers and thumb because of the unyielding overlying palmar aponeurosis. Careful dissection is necessary for removal because the tumor often envelops digital nerves and is much larger than is clinically apparent. Recurrence after marginal excision is unlikely.





Intraneural Lipofibromas


Intraneural lipofibromas are rare benign tumors that usually involve the median nerve. Patients present within the first 3 decades of life with a mass located in the palmar aspect of the hand or wrist, possibly with altered median nerve function (Fig. 77-2). Microscopically, fibroadipose tissue is seen infiltrating the epineurium, separating and compressing the fascicles. A conservative approach should be taken in treating these tumors. Incisional biopsy may be necessary for diagnosis. If extrinsic neural compression exists, surgical decompression should be performed by fasciotomy or carpal tunnel release. Intraneural excision may debulk the tumor, but this procedure is not recommended because intraneural fibrosis can increase the neural deficit. Malignant transformation is rare; however, intractable pain may result from some lesions and warrant tumor excision (Fig. 77-3). If a digital nerve is involved, en bloc excision with nerve grafting may be successful, although sensation would be altered (Fig. 77-4).






Giant Cell Tumor of the Tendon Sheath (xanthoma)


Giant cell tumors of tendon sheaths were first described in 1915 by Beekman, and some consider these to be the most common solid cellular hand tumors (Fig. 77-5). The reported age distribution is 8 to 80 years. These tumors occur in the hand more frequently than in any other part of the body, and they occur more often as firm lobulated masses on the volar lateral side of the index and middle fingers. Multiple xanthomas may be associated with hypercholesterolemia.



Xanthomas usually grow slowly and can remain the same size for many years. Pain and tenderness are rare. If xanthomas occur at a joint (often the proximal interphalangeal joint), they can become large enough to interfere with joint motion. They may rarely erode bone. Grossly, the tumors appear as well-encapsulated yellow or tan lobular masses. Histological sections reveal spindle cells, fibrous tissue, cholesterol-laden histiocytes, multinucleated giant cells similar to osteoclasts, and hemosiderin.


The lesions are benign, but 27% recur even after meticulous excision of the friable fragments. Risk factors for recurrence or persistence include adjacent degenerative joint disease, location at the finger distal interphalangeal and thumb interphalangeal joint, bony invasion, multifocal disease, and poor surgical technique. Excision often is difficult because the tumors may wind in and around the flexor tendons and their sheaths, the digital nerves, and even the extensor tendons and may involve three fourths of the circumference of involved digits; however, this benign lesion is considered surgically curable. Extensile surgical approaches are frequently required, and gentle blunt dissection should be performed to minimize fragmentation of the encapsulated tumor mass. Magnified vision is helpful to discover discolored synovial tumor, which must accompany the specimen.



Benign Tumors of Fibrous Origin


Fibrous tissue frequently proliferates in the hand as a response to local injury and is considered simple scar tissue; for this reason, the diagnosis of fibrous tumor must be made based on the appearance of the tumor, the age of the patient, the clinical behavior of the tumor, and its histological appearance. All tumors of fibrous origin may involve the hand; and although most are benign, they frequently are active or aggressive lesions with a tendency to recur after local excision. The differential diagnosis in benign fibrous tumors includes simple fibroma, recurring digital fibrous tumor of childhood, juvenile aponeurotic fibroma, Dupuytren contractures or nodules, fibromatosis or desmoid tumors, and pseudosarcomatous fasciitis. Fibromatosis or extraabdominal desmoid, and pseudosarcomatous fasciitis are especially aggressive tumors that usually involve the more proximal portions of extremities.




Juvenile Aponeurotic Fibroma or Calcifying Aponeurotic Fibroma


First described by Keasbey in 1953, juvenile aponeurotic fibroma is a benign fibrous tumor typically appearing in the hands or wrists of children and young adults. It also has been called calcifying aponeurotic fibroma because in older patients calcification of the cartilaginous component may be present, a feature that distinguishes it from other benign tumors of fibrous origin. Clinically, it is a painless, solitary, and mobile mass less than 4 cm in diameter, usually involving the palm (Fig. 77-6). The tumor usually is on the volar side of the hand and is connected to peritendinous tissues and fascia. It has no gender predilection and no tendency to involve the ulnar side of the hand, as do Dupuytren nodules. Juvenile aponeurotic fibromas tend to develop close to tendons and are able to infiltrate surrounding muscle and fat. On radiographs, calcifications can be seen within the soft tissue mass. Because juvenile aponeurotic fibroma has a distinct tendency for local recurrence after marginal excision, especially in younger children (50%), a wide excision, preferably without sacrifice of function, is recommended.






Glomus Tumor


A glomus body is a specialized neuromyoarterial receptor composed of an afferent arteriole, an anastomotic Sucquet-Hoyer canal, an afferent venule, actin-containing glomus cells surrounding the canals, intraglomerular retinaculum, and capsule. It functions as a dermal shunt that normally regulates skin temperature and blood pressure. Hyperplasia of one or more parts of the glomus body causes this tumor. Glomus cells are specialized perivascular muscle cells that are round or oval and have a dense, granular cytoplasm. Nonmyelinated nerve fibers that are intermixed with thick-walled capillaries are responsible for the lancinating pain.


Pain, cold sensitivity, and point tenderness are the characteristic symptoms of a glomus tumor, which was originally described by Wood in 1812 and histologically clarified by Masson in 1924. Direct pressure on the tumor by a small, firm object, such as a pinhead, causes excruciating pain (Love test), whereas pressure applied slightly to one side of it elicits no pain. Immersing the involved hand or digit in ice water also causes discomfort.


Glomus tumors usually are less than 1 cm in diameter, often being only a few millimeters in diameter, and may be visible through the overlying tissues as a deep red or purple discoloration. They occur more often in the hand (75%) than elsewhere and are located beneath the fingernail in 25% to 65% of patients (Fig. 77-8). Twenty-five percent are not subungual, however, and these may pose a difficult diagnostic problem. MRI and bone scans may prove helpful in diagnosing these tumors. Most of these tumors are benign; however, if the lesion exceeds 2.0 cm and histologic parameters suggest malignancy, then metastatic rates exceed 25%



These tumors can be removed with the patient under local anesthesia and should be accurately localized by marking the lesion just before surgery. Meticulous and complete excision of the usually well-encapsulated lesions is curative, although reoperation rates of 12% to 24% have been reported most likely from incomplete tumor extirpation.





Jun 5, 2016 | Posted by in ORTHOPEDIC | Comments Off on Tumors and Tumorous Conditions of the Hand
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