Bowenoid Malignant Onychopapilloma.
Kendall Billick, Carli Tucci, Erika Koh et al.
✦ AI-curated · Sources linked
Case in brief
A 52-year-old man presented with progressive longitudinal erythronychia of the thumbnail, characterized by increasing width, darkening, and distal keratotic changes. An excisional biopsy revealed histopathologic features consistent with onychopapilloma, but with additional full-thickness epithelial atypia showing a Bowenoid pattern. The diagnosis of malignant onychopapilloma was established based on these findings.
What made this case unusual
The case highlights a unique Bowenoid pattern of atypia in a malignant variant of onychopapilloma, which is not typically associated with this tumor.
Diagnostic / clinical pearl
Clinicians should consider the possibility of malignant onychopapilloma in cases of longitudinal erythronychia that exhibit atypical histopathologic features.
Why it matters
This case underscores the need for awareness of malignant variants of onychopapilloma, which may present with atypical features that challenge traditional perceptions of the tumor's benign nature.