A case report: false hCG trail: dysgerminoma imitates gestational trophoblastic disease.

Ovarian malignant germ cell tumors (MOGCTs) represent approximately 5% of all ovarian malignancies. However, in women aged 10 to 30, they account for up to 70% of ovarian neoplasms and may occasionally occur bilaterally. Roughly one-third of MOGCTs are dysgerminomas. These tumors may also be hormonally active. Gestational trophoblastic neoplasia (GTN) is a spectrum of rare tumors arising from abnormal trophoblast proliferation, involving invasive mole, choriocarcinoma, placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT) - characterized by elevated levels of human chorionic gonadotropin (hCG). This case report presents a young patient with a hormonally active dysgerminoma initially misdiagnosed as a GTN due to elevated and progressively rising hCG levels, along with clinical symptoms. After the misdiagnosis, the patient was initially treated with monochemotherapy and after the completion of the therapy, hCG levels did not reach negativity. The patient presented with recurrence of hCG levels elevation, and for suspected GTN the chemotherapy was further escalated. The correct diagnosis was only established after thoracotomy excision of the pulmonary lesion, which turned out to be a pulmonary metastasis of dysgerminoma. Thereafter, the patient was promptly treated according to the recommended guidelines and is currently in remission. It is necessary to maintain a broad differential diagnosis in patients with low but persistent hCG levels. GTN is often the first suspected entity, but we must consider the possibility of hormone-producing ovarian tumors, including dysgerminomas.