Clinical, dermoscopic, and pathologic features of onychopapilloma: A review of 47 cases.

BACKGROUND: Onychopapilloma is a benign neoplasm of the nail bed and the distal matrix. Although not uncommon in our experience, only up to 32 cases of this tumor have been reported in the literature.

OBJECTIVE: We sought to review the clinical, dermoscopic, and pathologic features of onychopapilloma.

METHODS: We retrospectively analyzed the clinical features of 47 patients with pathologically confirmed onychopapilloma diagnosed within the last 5 years, and reviewed the published literature.

RESULTS: The most common clinical presentation was longitudinal erythronychia (n = 25); followed by longitudinal leukonychia (n = 7); longitudinal melanonychia (n = 4); long splinter hemorrhages without erythronychia, leukonychia, or melanonychia (n = 8); and short splinter hemorrhages without erythronychia, leukonychia, or melanonychia (n = 3), with subungual mass (n = 47) and distal fissuring (n = 11). Pathology was consistent with acanthosis of the nail bed and distal matrix, with matrix metaplasia underlying distal subungual hyperkeratosis.

LIMITATIONS: This was a retrospective analysis.

CONCLUSION: To our knowledge, our series of onychopapilloma is the largest so far. Among various clinical presentations, longitudinal erythronychia is the most common. Dermoscopy of the free edge of the nail plate showing a small subungual keratotic mass where the band reaches the nail plate margin provides a clue for the diagnosis.