Cytodiagnosis of vaginal endodermal sinus tumor. A case report

Endodermal sinus tumor (EST) of vaginal origin is extremely rare, and few previously published reports have described the cytology of this tumor.

A high serum alpha-fetoprotein (AFP) level and magnetic resonance imaging findings in a 10-year-old female suggested EST of the lower genital tract. Laparotomy revealed EST occupying the pelvic cavity. The patient died on the 17th postoperative day due to complications from disseminated intravascular coagulation. Autopsy was performed immediately after death. The tumor originated in the posterior vaginal wall directly below the ectocervical area. Both ovaries were involved, and the tumor proliferated to occupy the cavity of the pelvis minor. A vaginal smear, obtained on two occasions, revealed severe necrosis with few cells, and a diagnosis could not be made. An imprint smear of the tumor obtained during surgery showed relatively characteristic cytologic findings of EST. Immunocytochemical and immunohistochemical studies revealed staining positive for AFP.

Vaginal EST usually occurs in patients under 3 years of age. This 10-year-old patient was the oldest among the reported cases. Vaginal EST is clinically similar to sarcoma botryoides and clear cell carcinoma, and a differential diagnosis is necessary. Immunocytostaining for AFP is essential for a definitive cytologic diagnosis of EST.