Tubulovillous Adenoma of Vagina With Both KRAS and APC Mutations: Case Report

Adenomatous polyps of the vulva and vagina are extremely rare. We report a case of a 74-yr-old women with a tubulovillous adenoma occurring in the vagina, and a second one occurring later in the vulva. Tumor cells in both lesions were CK7(-), CK20(+), CDX-2(+), and showed intact mismatch-repair proteins. A G13D (c.38G>A, p.Gly13Asp) mutation in the KRAS gene was identified in both masses. As well, a novel frameshift truncating mutation (c.4320delA, p.Pro1441fsTer32) in the APC gene was detected only in the vaginal mass, ruling out the possibility that the vulvar mass was a local recurrence of the vaginal mass. This is the first identification of KRAS and APC gene mutations in adenomatous polyps involving the female lower genital tract.