Extramammary Paget’s disease (EMPD) is an extremely rare cutaneous malignancy that represents a slow-growing, erythematous, ulcerative or eczematous plaque in areas of the body that possess a high concentration of apocrine glands. It is frequently observed in the genital region of Caucasian females, with the perianal region representing an uncommon site of involvement. Here, we report a case of primary extramammary Paget’s disease in the perianal region of a 55-year-old male, offering new insights into this elusive and poorly understood dermatologic condition.

A 55-year-old male sought consultation for a solitary, well-defined, irregularly shaped, erythematous to violaceous, ulcerated plaque in the perianal area of one-year duration. A clinical diagnosis of primary EMPD was confirmed by histopathologic findings of Paget cells, a cytokeratin 7 positive/cytokeratin 20 negative immunophenotype, and the absence of underlying malignancy. A wide excision with negative margin control and a bilateral V-Y fasciocutaneous advancement flap were performed with good results.

Extramammary Paget’s disease is a rare but insidious dermatologic malignancy often easily disregarded as a benign inflammatory condition. It underscores the need for clinicians to maintain a high index of suspicion to provide an early, accurate diagnosis, leading to a multidisciplinary treatment approach to prevent potential complications.