Primary extramammary Paget’s disease of the perianal region: a case report and review of the literature

Extramammary Paget’s disease (EMPD) is a rare cutaneous adenocarcinoma that arises in apocrine gland–bearing regions, most commonly the vulva, scrotum, or perianal skin. Perianal Paget’s disease (PPD) represents around one-fifth of EMPD cases and is often associated with underlying malignancy. We report a 63-year-old male with hypertension and dyslipidaemia who presented with a three-year history of an itchy erythematous plaque around the perianal region. Punch biopsy confirmed EMPD. Systemic evaluation, including contrast-enhanced CT of the chest, abdomen, and pelvis, tumour markers (AFP, CEA, PSA), and colonoscopy, excluded synchronous malignancy. 
Following multidisciplinary team (MDT) discussion, the patient underwent wide local excision (WLE) of the lesion with protective sigmoid loop colostomy. Histology demonstrated intraepidermal proliferation of Paget cells without dermal invasion. The postoperative course was uneventful, and the patient was referred for adjuvant radiotherapy. This case highlights the importance of early biopsy, complete staging, and WLE for localized perianal EMPD. Long-term post-therapeutic surveillance remains imperative due to the high propensity for local recurrence characteristically observed in these primary variants.