Content area
Full Text
Adenosquamous carcinoma is a variant of metaplastic carcinoma characterized by presence of both squamous cell carcinoma and adenocarcinoma within the same tumor, seen either admixed or as separate areas within the tumor.1-3 Adenosquamous carcinoma of the colon, rectum, and anus is exceedingly rare, with anal adenosquamous carcinoma being addressed only in a single United States population based study published on this malignancy so far in the literature. In this study, from 244,410 colorectal and anal cancers registered in a 20-year period (1973-1992) by Surveillance, Epidemiology, and End Results Program (SEER), 145 cases were registered as adenosquamous carcinoma of colon, rectum, and anus, with only six primary anal adenosquamous carcinomas (incidence of 0.002%)Л Two additional studies in Taiwanese and Chinese populations from Hong Kong reported outcome results on anal adenosquamous carcinoma with 6/27 patients and 1/18 patients with anal adenosquamous cell carcinoma, respectively.24 4 present a case of adenosquamous carcinoma of the anus which poses a treatment challenge.
A 54-year-old female presented with a severalmonth history of increasing anorectal pain associated with bright red blood per rectum. Examination revealed a 3-cm right anal margin mass concerning for malignancy with palpable inguinal lymphadenopathy. The patient proceeded with an incisional biopsy. On microscopic examination of the anal margin mass, soft tissue without overlying epithelium was seen infiltrated by well-defined invasive tubular glands surrounded by poorly differentiated sheets of carcinoma cells. Immunophenotypically, glands and sheets of poorly differentiated carcinoma were positive for cytokeratin 7, glands were positive for cytokeratin 20, while p63 and p40 were strongly...