An unknown mass: the differential diagnosis of digit tumors.

There is little discussion of tumors arising in the digits in the dermatology literature. The patient with an undifferentiated mass of the finger is frequently encountered in the clinic, and variances in presentation of common and uncommon entities pose a challenge that may prompt further investigation for proper diagnosis and treatment. In this review, the authors illustrate the approach and work-up of an unknown digit mass of a 45-year-old female patient. They go on to discuss the presentation and treatment of common tumor lesions of the finger likely to be encountered in the dermatologist's clinic including: ganglion cyst/mucous cyst, giant-cell tumor, verruca vulgaris, epidermal inclusion cyst, poroma, porocarcinoma, squamous cell carcinoma, basal cell carcinoma, melanoma, infantile digital fibromatosis, acquired digital fibrokeratoma, Koenen's tumor, schwannoma, cutaneous neurofibroma, pyogenic granuloma, hemangioma, glomus tumor, epithelioid sarcoma, and metastatic disease.