Perianal Extramammary Paget’s Disease: More Than Meets the Eye

Excerpt

A 75-year-old man was initially evaluated for a 1-year history of perianal pruritus that was refractory to multiple topical therapies. He had a sharply demarcated, erythematous and scaly rash involving the left perianal skin, originating from the left hemi-circumference of the anal verge and extending anteriorly, laterally and posteriorly to involve a 6 cm × 4 cm area of skin (Fig. 1). A punch biopsy of the lesion confirmed extramammary Paget’s disease (EMPD). Immunostaining of the biopsy was positive for cytokeratin (CK)7 and GATA3, weakly positive for cytokeratin 20, and negative for CDX2 and prostate-specific antigen (PSA), all consistent with likely primary EMPD. Patient’s past history was notable for coronary artery disease and prostate cancer, for which he had undergone prostatectomy. His recent serum PSA had been unremarkable at 0.02 ng/mL. PSA immunostaining of the punch biopsy was negative, as was urine cytology, excluding underlying urothelial intraepithelial neoplasia. Further evaluation to exclude an underlying malignancy included computed tomography (CT) of the abdomen and pelvis, which was unremarkable. Colonoscopy from several months prior to initial presentation was likewise negative.

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