Soft Tissue Tumors of the Hand and Wrist




BASIC PRINCIPLES


Soft tissue lesions of the hand and wrist may be divided into two groups: tumor-like lesions and true neoplasms. The true neoplasms may be subdivided into benign and malignant tumors. Given the intricate anatomy of the hand and wrist, the presentation and treatment of these lesions may differ from those found in other locations of the body. However, the same general principles of tumor workup apply ( Box 63-1 ).



BOX 63-1




  • 1.

    Detailed history and physical


  • 2.

    Obtain necessary imaging and lab work (complete blood cell count, chemistry panel, coagulation panel, erythrocyte sedimentation rate, C-reactive protein, and so on)


  • 3.

    Biopsy


  • 4.

    Diagnosis


  • 5.

    Collaboration with dermatology, pathology, and medical and radiation oncology as needed



TUMOR WORKUP


The evaluation begins with a detailed history and physical examination. Pertinent medical conditions (renal disease, endocrine disorders, prior malignancies), changes in consistency or neurologic symptoms, and antecedent trauma should be noted. Rapid growth, night pain, constitutional symptoms such as fevers, chills, or unexplained weight loss, and/or an increase in pain should raise suspicion of malignancy.


Finally, five main categories should be used to describe a lesion: size of the lesion, characterization of texture, inspection of skin overlying the mass, palpation for epitrochlear or axillary lymph nodes, and a comprehensive neurologic and vascular examination. Routine complete blood count, chemistry panel, and coagulation studies are useful. If there is evidence of malignancy, collaboration with pathology, medical oncology, and radiation oncology professionals is necessary.




IMAGING


One should start with plain radiographs to rule out bony involvement and to obtain key information for soft tissue masses (e.g., phleboliths in hemangioma and cortical disruption of an invasive sarcoma). Magnetic resonance imaging (MRI) provides useful information regarding soft tissues. T1-weighted images provide detailed anatomic information, whereas fat-suppressed T2 imaging identifies subacute hematoma, purulence, and malignant change (except fibrous tumors). Several variations of T2-weighted images such as spin echo, fast spin echo, and short tau inversion recovery (STIR) may alter fluid sensitivity. Gadolinium is often used as an intravenous contrast medium to determine vascularity of structures. The malignant tumor workup involves a chest x-ray, total body scintigraphy to rule out metastasis, and computed tomography (CT) of the chest/abdomen/pelvis ( Table 63-1 ). For vascular lesions, magnetic resonance angiography (MRA) and/or conventional angiography are commonly used.



TABLE 63-1

Imaging Modalities












































Imaging Method Timing Purpose
Radiographs Initial workup—always


  • Rule out bony involvement



  • Soft tissue effect

MRI Secondary workup—when mass is in close proximity to vital structures (e.g., tendons, vessels, and nerves)


  • Identify characteristics of soft tissue lesion



  • Identify extent of tissue invasion

T1-weighted Workup Anatomic differentiation
T2 fat-suppressed Workup


  • Identify:



  • Subacute hematoma



  • Purulence



  • Malignant change

FDG-PET Sarcoma workup Grading, prognostication
Chest x-ray Metastatic workup Metastasis surveillance
Total body scintigraphy Metastatic workup Sarcoma staging
CT chest/abdomen/pelvis Metastatic workup Sarcoma staging (esp. epithelioid and myxoid liposarcoma)
Magnetic resonance angiography Vascular lesion workup Vascular lesions

CT, computed tomography; FDG-PET, fluorodeoxyglucose-positron emission tomography; MRI, magnetic resonance imaging.




BIOPSY


The biopsy is the final step in diagnosis. If there is potential for malignancy, the surgeon qualified to perform the definitive procedure should be the surgeon performing the biopsy. In addition, the biopsy should be performed at the institution where all subsequent treatment and monitoring are to be performed, since ultimate survival is worse when the biopsy and definitive management are performed at different institutions.


Every effort should be made to limit tumor spread and morbidity. There are four methods of dissection: intralesional, marginal, wide, and radical ( Table 63-2 ). In general, the more aggressive dissection methods are reserved for more aggressive tumors and vice versa. Longitudinal incisions are preferred, since the incision must be kept in line with the ultimate incision if radical re-excision or reconstruction is necessary. One should apply a tourniquet for adequate hemostasis and avoid using the Esmark wrap for exsanguination to prevent venous and lymphatic spread of tumor cells. Elevation of the extremity for proper exsanguination is sufficient. The dissection should be limited to a single anatomic compartment, if possible, with meticulous hemostasis and closure of all tissue planes. Because infections often mimic neoplasms, cultures should always be obtained.



TABLE 63-2

Tumor Dissection Definitions



















Dissection Method Dissection Plane
Intralesional Through the tumor
Marginal Through the tumor “reactive zone” or pseudocapsule
Wide Through cuff of normal tissue, intracompartmental
Radical Extracompartmental, includes removal of entire contents of affected compartment


Alternatives to biopsy include fine-needle aspiration (FNA) and core needle biopsy; however, these methods are preferable only with tumor-like conditions. Because of the small size of tumors in the hand and wrist, excisional biopsy is usually the preferred method.




TUMOR-LIKE CONDITIONS


Ganglion Cyst


The ganglion cyst is the most common soft tissue lesion of the hand and wrist. This mucin-filled cyst remains connected to a nearby joint capsule by a small stalk, which allows cyst contents to flow between the two spaces, noticeably fluctuating its size. There are four typical locations where ganglion cysts are most likely to arise: dorsal wrist ( Fig. 63-1 ), volar wrist ( Fig. 63-2 ), dorsal distal interphalangeal joint (mucoid cyst), and volar metacarpophalangeal joint (volar retinacular cyst) (see Fig. 63-2 ). The dorsum of the wrist, originating from the scapholunate interosseous ligament, is the most common location.




FIGURE 63-1


Volar ganglion . Note volar ganglion causing clawing of digits secondary to compression of the ulnar nerve in Guyon’s canal.



FIGURE 63-2


Ganglion cysts . ( A–C ) Dorsal, lateral, and intraoperative views of a bilobed dorsal wrist ganglion cyst. ( D–F ) Intraoperative views of a volar retinacular cyst. Note the stalk in F. ( G and H ) Intraoperative finding of intratendinous ganglion within extensor digitorum communis to long finger tendon.


Conservative management begins with reassurance of the benign nature of the lesion, observation, splinting, or aspiration, in which success rates range from 30% to 50%, even with multiple aspirations. Surgery is reserved for persistently symptomatic cysts. Complete excision of the ganglion must include the entire stalk leading into the joint space to minimize the risk of recurrence. A cuff of capsule is excised with the stalk and left open to prevent loss of motion. After a dorsal ganglion excision, the patient’s wrist should be immobilized for 1 to 2 weeks in slight flexion, whereas after a volar ganglion excision, the patient’s wrist should be immobilized in slight extension to prevent stiffness from postoperative scarring. After complete excision, recurrence is low, but incomplete excision may lead to rates as high as 40%. Recent studies have reported successful outcomes in 95% of patients undergoing arthroscopic surgery.


Giant Cell Tumors of the Tendon Sheath


Giant cell tumors of the tendon sheath are the second most common lesion in the hand and wrist. These benign, slow-growing neoplasms histologically resemble intra-articular, pigmented villonodular synovitis ( Fig. 63-3 ). Middle-aged and elderly patients usually present with a nontender, fixed mass on the volar side of the fingers in the vicinity of the distal interphalangeal joints. Giant cell tumors of the tendon sheath may become painful by impinging on digital nerves or by mechanically interfering with joint function. The tumor is often multinodular and may be distinguished from ganglion cysts in that they do not transilluminate.




FIGURE 63-3


Giant cell tumor . Preoperative and intraoperative views of giant cell tumor of the tendon sheath affecting the distal phalanx of the index finger.


Although giant cell tumors carry no risk of malignant transformation, they may be locally aggressive and grow large. Rarely is there any bony invasion, but pressure erosion of the cortex is possible in large tumors. Marginal excision using standard digital incisions, with care taken to excise satellite lesions, is curative. However, recurrence rates range from 5% to 50%, probably owing to incomplete primary excision or multiple discrete tumors.


Epidermal Inclusion Cysts


Epidermal inclusion cysts, the third most common hand tumor, are keratin-filled cysts resulting from invagination of epithelium into the subdermal layer. These cysts are likely the result of puncture wounds, but often the patient has no recollection of a minor traumatic event. Epidermal inclusion cysts are well circumscribed, firm, and mobile, and located just beneath the skin, usually associated with a skin punctum. The most common location is the fingertip. There is no risk of malignant degeneration, but the cysts progressively enlarge and may become infected. Marginal excision is curative and includes an ellipse of skin if the cyst is very superficial or adherent to overlying skin. Recurrence rates are extremely low.


Fibromas of the Tendon Sheath


Fibromas of the tendon sheath are similar to giant cell tumors of the tendon sheath but with much less cellularity and without xanthoma or giant cells. They are encapsulated lesions that contain groups of fibroblasts surrounded by collagen and other stroma, attached to the tendon sheath. These slow-growing, painless lesions do not carry a risk of malignant transformation, but may grow to encompass the entire length of the finger. Marginal excision is curative. However, recurrence within 4 months of treatment has been observed at a rate of 24%.


Tumors of Adipose Tissue


Lipomas


Lipomas are benign proliferations of adipocytes. They are rubbery, mobile masses that do not transilluminate and are circumscribed by a layer of loose areolar tissue ( Fig. 63-4 ). Generally painless, lipomas may become symptomatic by mass effect in the carpal tunnel, Guyon’s canal, the thenar and hypothenar eminences, and other deep spaces.




FIGURE 63-4


Phalangeal lipoma . Preoperative and intraoperative views of lipoma of the proximal phalanx of the small finger.


Marginal excision should proceed along the plane of the surrounding loose areolar layer ( Fig. 63-5 ). Because the frequency of malignant degeneration is low, lipomas are excised only when they cause functional or cosmetic impairment. Recurrence after complete excision is rare.




FIGURE 63-5


Forearm lipoma . Marginal excision of forearm lipoma.


Lipomas with rapid growth, increasing pain, or large size should prompt suspicion of malignant disease.


Liposarcomas


MRI findings of invasion into local tissues or disfigurement of tissue planes surrounding the mass should also raise concern for liposarcoma. Liposarcomas may be divided into five subtypes: well differentiated, myxoid, round cell, dedifferentiated, and pleomorphic. The myxoid and round cell varieties are seen in younger adults, whereas the other subtypes are seen mostly in the sixth decade of life. Overall, liposarcomas have a 5-year survival rate of 73%. Wide excision or amputation with adjuvant radiation therapy is the treatment of choice. In high-grade lesions with metastatic spread, adjuvant chemotherapy should also be considered. A study by Kilpatrick and colleagues reported the metastatic rate and morbidity rate of myxoid liposarcoma and round cell liposarcoma to be 35% and 31%, respectively. Factors associated with a poorer prognosis included age greater than 45 years, percentage round cell differentiation, and presence of spontaneous tumor necrosis.




VASCULAR TUMORS


Aneurysms


Aneurysms are focal dilatations of a vessel wall. True aneurysms are dilatations containing all three layers of the arterial wall: endothelium, tunica media, and tunica adventitia. This weakening in the vessel wall is usually caused by repetitive blunt trauma. False aneurysms are often a consequence of penetrating injuries to the vessel wall in which a hematoma at the site of injury organizes, recanalizes, and forms a new outer wall. In terms of true aneurysms of the hand, ulnar artery involvement in the hypothenar area is most common. For both true and false aneurysms, patients may complain of cold intolerance, painful digits, or paresthesias. Examination usually reveals a pulsatile lesion. Left alone, aneurysms may expand or form a thrombus, with embolization to the digits. The imaging modality of choice is arteriography, although CT or MRA may be useful as well.


Treatment options for acquired aneurysms include ligation or excision with reversed vein graft repair, depending on the importance of the artery for distal perfusion. Preoperative angiography is useful to elucidate collateral flow in addition to intraoperative brisk backflow of the distal stump of the artery. Current recommendations for reconstruction are based, in part, on age of the patient and whether pre-excision evidence exists for reduced collateral circulation.


Glomus Bodies


The glomus body is an arteriovenous shunt that regulates temperature and blood flow throughout the body but most commonly in the fingertips and nail beds ( Fig. 63-6 A–D). Patients with glomus tumors complain of radiating pain brought on by cold temperature, such as the application of cool spray in the examination room. Occasionally, plain radiographs indicate mild scalloping of the terminal phalanx at the site of the lesion. An MRI can be useful in the detection of these lesions ( Fig. 63-6 B). Marginal excision is curative and brings immediate symptomatic relief. Care must be taken to search for additional small glomus bodies. Recurrence is uncommon.


Jul 10, 2019 | Posted by in ORTHOPEDIC | Comments Off on Soft Tissue Tumors of the Hand and Wrist
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