Subungual Keratoacanthoma: Typical and Atypical Presentations of an Uncommon Nail Tumor

Keratoacanthoma (KA) is a group of tumors of epidermal origin with controversial nature. Subungual keratoacanthoma (SUKA) is a rare and destructive variant with more aggressive behavior. SUKA appears as a rapidly growing, painful tumor beneath the nail plate that rapidly progresses to a mass that can measure up to 2 cm. The toe location is unusual. The diagnosis must be made based on the correlation of clinical, radiological, and histopathological findings.

We present two cases of patients diagnosed with SUKAs with different clinical presentations which ranged from very typical to uncommon one. Both cases were treated with simple excision without recurrences.

SUKA is a rare subungual tumor. Nail bed location represents a more difficult diagnostic challenge. SUKA should be suspected in the context of persistent and progressive pain on a finger or toe, once more frequent painful tumors have been ruled out.