A Large Hyperkeratotic Plantar Lesion: An Atypical Presentation of Acquired Digital Fibrokeratoma

Acquired digital fibrokeratoma (ADFK) is a benign fibrous proliferation that typically presents as a small, solitary papule on a digit, often surrounded by a characteristic collarette of scale. Giant variants are uncommon and may pose diagnostic challenges, particularly when arising in atypical locations. We report a 56-year-old man with a 14-year history of a progressively enlarging hyperkeratotic lesion on the plantar surface of the foot. Excisional biopsy revealed a lesion measuring 4.4 × 2.9 × 1.5 cm, and histopathologic evaluation confirmed the diagnosis of ADFK. This case highlights that ADFK may present as a large plantar lesion with atypical clinical features and underscores the importance of histopathologic evaluation in morphologically unusual acral tumors.