A pelvic mass on ultrasonography and high human chorionic gonadotropin level: not always an ectopic pregnancy.

A 24-year-old patient with 7-week amenorrhoea consulted for vaginal bleeding without abdominal pain. Ultrasonography revealed a 7 × 4 cm solid right pelvic mass. There was no visible intrauterine gestational sac. The serum β-human chorionic gonadotropin (β-hCG) level was 11 998 IU/l. Emergency laparoscopy was performed for a presumptive diagnosis of ectopic pregnancy. At laparoscopy, the right ovary was enlarged with a non-haemorrhagic 7 × 4 cm solid lesion, which was resected. The histological diagnosis was a dysgerminoma with immunohistochemistry showing nests of syncytiotrophoblastic cells, which were the origin of the hCG production. There was no pregnancy, either intrauterine or ectopic. There was no evidence of metastasis from the dysgerminoma on the positron-emission tomography scanner. The patient underwent a second procedure for surgical staging of this ovarian germ-cell tumour. This ovarian dysgerminoma was staged FIGO 1A, and the patient did not receive adjuvant therapy. There was no recurrence at the last 8-month follow-up.