An unusual clinical presentation of a pure yolk sac tumor of the ovary: case report.

Yolk sac tumor (YST) of the ovary is a rare neoplasm, which belongs to the group of ovarian germ cell tumors. It most commonly occurs in children and young women and it is characterized by high malignancy given its premature metastasis. An early diagnosis is important but not easy. An 18-year-old girl came to the authors' observation for amenorrhea lasting approximately 16 weeks. Abdominal examination revealed a painless palpable mass in the right lower abdomen. At admission ultrasonography (US) and magnetic resonance imaging (MRI) showed a complex mass of the right adnexa with a diameter of about 15 cm. The alpha-fetoprotein (AFP) serum level was elevated to 960 UI/ml. Fertility-sparing surgery was undertaken and the histopathology revealed a Stage IA pure YST. Chemotherapy was avoided and an intensive 36 months follow-up was performed without clinical and radiological evidence of recurrence. This is the first case report of a pure YST of the ovary presented with amenorrhea. It is also a very interesting case for its Stage IA despite prolonged duration of symptoms and AFP high levels.