Invasive extramammary Paget's disease of the scrotum: A case report.

Extramammary Paget's disease is a rare cutaneous malignancy that typically presents as carcinoma in situ, and instances of invasive extramammary Paget's disease are exceptionally rare. Herein, we describe a rare case of invasive extramammary Paget's disease of the scrotum. A 91-year-old male presented with an over 10-year history of a granulomatous rash with serous discharge, refractory to various topical therapies and weekly wound care. Physical examination revealed a well-demarcated, erythematous, mamillated, eroded plaque with arcuate borders involving the left inguinal crease and scrotum. A punch biopsy showed intra-epidermal and invasive carcinoma with focal pagetoid spread and intracytoplasmic mucin. The favored diagnosis was primary, invasive extramammary Paget's disease. The patient underwent a wide local excision and routine imaging surveillance and remains recurrence-free at 1-year follow-up. Given that extramammary Paget's disease remains commonly misdiagnosed, leading to delays in treatment, dermatologists should be aware of this diagnosis, particularly for elderly patients presenting with non-specific genital lesions recalcitrant to routine treatment.