Atypical and giant proliferating pilomatrixoma of the eyelid: a clinicopathological report.

Background: Pilomatrixoma is an uncommon benign skin neoplasm originating from the hair follicle. Here, we report a rare case of giant and atypical proliferating pilomatrixoma affecting the eyelid.

Case presentation: A 47-year-old male presented with a solitary, giant mass on his left upper eyelid, which had recently shown progressive enlargement. The lesion appeared well-circumscribed with a firm consistency, and measuring 7 × 10 cm. Orbital computed tomography scan revealed no intraorbital extension. The lesion was surgically excised. Histopathological examination identified the mass as an atypical proliferating pilomatrixoma, characterized by a minimal infiltrating margin of the deep plane and focal cytological atypia of the basaloid cells. No recurrence was observed up to one year postoperatively.

Conclusions: Pilomatrixoma is a rare periocular tumor with potential for malignant transformation, often mimicking other lesions in this region. Therefore, any enlarging masses in this area should be excised for histopathological evaluation to rule out malignancy.