Primary vaginal adenocarcinoma of intestinal type arising from an adenoma:Case report and review of the literature

A 1 cm polypoid lesion was encountered on the posterior vaginal wall in a 5 6-year-old woman with no history of diethylstilbestrol exposure that on mic roscopic examination was a moderately differentiated adenocarcinoma of inte stinal type. The tumor was cytokeratin 20 and carcinoembryonic antigen posi tive and negative for cytokeratin 7. Mucin histochemistry demonstrated the presence of o-acetylated sialomucin, a specific marker of large intestinal differentiation. The initial interpretation favored a metastasis from a col onic adenocarcinoma, but clinical investigations showed no evidence of a pr imary gastrointestinal lesion. The morphology, histochemical, and different ial cytokeratin profile led to the lesion being reinterpreted as a primary intestinal-type adenocarcinoma of the vagina arising from a tubular adenoma . Although a very rare tumor, awareness of this lesion is important as it m ust be distinguished from metastatic adenocarcinomas from other sites.