HPV related cloacogenic carcinoma of the anal canal with divergent histomorphology

Cloacogenic carcinoma also known as basaloid squamous cell carcinoma is a rare anorectal tumor presenting with varied histomorphology. In this case report, we describe a case of 58-year-old man presenting with bleeding per rectum and pain. A polypoidal tumor was noted in anal canal which on microscopy was diagnosed to be cloacogenic carcinoma with transitional carcinoma-like, basaloid and mucinous patterns. An unusual finding in the present case was the presence of signet ring cells in the mucinous areas. A thorough knowledge of the wide histomorphological spectrum of the tumor and a limited IHC panel are crucial for the diagnosis. Here, we also present a review of literature and describe in detail the origin and histopathological features of the tumor.