Germ cells tumours most frequently occur in the gonads. Extragonadal localisation is rare and concerns mainly the mediastinum, retroperitoneum and pineal.
We present the first description of a patient with a mixed germ cells tumour located primarily in the thyroid. A 35-year-old man in a good clinical condition was admitted to diagnose metastasis revealed in an X-ray of his lungs. Abnormal laboratory tests showed high concentrations of beta-HCG and LDH. Ultrasound examination revealed: hypoechogenic area 8 × 4 × 5 mm in the left testicle, and enlarged left thyroid lobe with echogenically heterogenous mass. In cytological examination of the thyroid, carcinomatous cells were found, which suggested metastasis. A diagnosis of cancerous spread of testicular cancer to the lungs and thyroid was made. The left testicle, with spermatic cord, was removed, yet in the histopathological examination no carcinomatous cells were found. Rescue chemotherapy, according to the BEP scheme (bleomycin, etoposide, cisplatin) was started, but during its course the patient died. Histopathology disclosed primary mixed germ cells tumour in the thyroid, predominantly with carcinoma embryonale and focuses of choriocarcinoma. Extragonadal germ cells tumours rarely occur in the thyroid. In medical literature, some cases of teratomas and a single case of yolk sac tumour in the thyroid have been described. The presence of choriocarcinoma was responsible for the high serum concentration of beta-HCG. Surgery of germ cells tumours proves insufficient. The conventional chemotherapy is based on cisplatin. In conclusion, extragonadal germ cells tumours are rare, but should be considered while co-existing with elevated markers such as: AFP, beta-HCG and lack of abnormalities in the gonads. (Endokrynol Pol 2012; 63 (5): 388-390)