Perianal Paget Disease: Different Entities With the Same Name

Extramammary Paget disease (EMPD) is a rare form of cancer that involves skin areas rich in apocrine glands. The common sites of occurrence include the vulva, perianal region, perineum, and axilla. Perianal Paget disease (PPD) is a subset of EMPD, which arises in the perianal skin. The disease commonly presents with a thickened plaque-like lesion with erythema or white scaly appearance. It is generally classified into two categories based on the origin of the tumor cells: (1) primary PPD if the tumor arises from intraepidermal cells and (2) secondary PPD if cancer originates from the underlying colorectal or urinary tract neoplasm. Due to its rarity, only a few sporadic case reports have been published in the literature, and treatment methods are yet to be standardized. In light of this, we report two PPD cases with different etiopathogenesis and staging: one involved only the perianal skin without regional or metastatic disease, and was not accompanied by visceral adenocarcinomas although there was a previous history of sigmoid adenocarcinoma; the other was probably secondary to an anal canal tumor spreading with disseminated disease involving the perianal and perineum area with bilateral inguinal, pelvic lymph node, and liver metastasis. The treatment plans and the outcomes of both cases were necessarily different from each other.