Details
Biopsy of low rectal mass.
Squamous carcinomas can arise from the anal transition zone, which is immediately above the dentate (pectinate) line, and this is therefore quite compatible with a primary. Also possible, but deemed less likely in this case, is spread from a gynecological-tract primary squamous cell carcinoma.
As these tumors can also be HPV-related, it is always advisable to a) ensure there was no known previous source for this tumor and b) advise a full gynecological exam - especially pap smear - to ensure there is no HPV related disease or overt tumor in the vagina or cervix.
The rectal mucosa included shows marked reactive changes and congestion, but there has been no previous treatment, especially radiation (which would have been a good thought). The epithelium is not dysplastic and has restitutional changes (the tip-off).