A 58-year-old woman complains of recent swelling in her
vagina. There is a past medical history of prenatal exposure
to diethylstilbestrol. Physical examination reveals a 3-cm fi rm
mass in the anterior wall of the upper vagina. Biopsy of the
vaginal mass will most likely show which of the following
pathologic fi ndings?
(A) Clear cell adenocarcinoma
(B) Endodermal sinus tumor
(C) Granular cell tumor
(D) Mucinous adenocarcinoma
(E) Squamous cell carcinoma