A case of anal canal cancer with pagetoid spread and inguinal lymph node involvement

We report a rare case of pSM anal canal cancer with pagetoid spread and inguinal lymph node involvement. A 74-year- old woman was admitted to our hospital complaining of a perianal erythematous lesion. Preoperative skin biopsy revealed an infiltration of pagetoid cells and signet-ring cell carcinoma cells, which were positive for CK20 and negative for GCDFP 15 by immunohistochemical stainings. Colonoscopy demonstrated an elevated lesion located just above the dentate line. Total pelvic exenteration with lateral and inguinal lymph node dissection followed by skin reconstruction with gluteal thigh flap was performed. Histological examination of the anal tumor revealed moderately differentiated adenocarcinoma infiltrating the submucosa( pSM) with left lymph node involvement. We should note that pSM anal canal cancer with pagetoid spread might cause inguinal lymph node metastasis, even though such cases have rarely been reported in the literature.