Hand and Wrist Neoplasms and Soft-Tissue Masses
Benign by frequency, malignant by exception
Ganglions. The most common hand mass. Dorsal wrist ganglions arise near the scapholunate interval, volar ones from the radiocarpal joint or FCR sheath. Mucous cysts occur at the DIP joint in osteoarthritis and can groove the nail. Asymptomatic ganglions may be observed; excision with a capsular cuff lowers recurrence.
Bone tumors. Enchondroma is the most common primary bone tumor of the hand, typically a central lytic lesion in a proximal phalanx. Multiple lesions suggest Ollier disease or Maffucci syndrome, both with malignant potential. Chondrosarcoma is the key differential, suggested by pain, cortical destruction, and soft tissue extension.
Soft tissue tumors. Giant cell tumor of tendon sheath is a firm, lobulated, slow-growing volar digital mass; marginal excision suffices with modest recurrence. Glomus tumor causes subungual pain, cold sensitivity, and point tenderness, with high MRI sensitivity. Schwannoma is eccentric to the nerve and can be shelled out; neurofibroma is inseparable from the nerve and suggests NF1.
Malignancy red flags. Size over 5 cm, deep to fascia, rapid growth, night pain, and recurrence. Subungual melanoma (Hutchinson sign) and epithelioid sarcoma are classic hand malignancies. Image with MRI before biopsy, and perform biopsy only at the definitive treating center.
Traps: excising a mass without imaging; mistaking a glomus tumor for chronic paronychia; and declaring an enchondroma benign without checking for multiple lesions.
Rule of thumb: a mass over 5 cm, deep to fascia, or painful at night earns an MRI before any knife.