A rare case of combined placental site trophoblastic tumour with mature cystic teratoma and mixed germ cell tumour in the testis.
A 20-year-old male presented with persistent right testicular pain. Following ultrasound detection of testicular nodules and biopsy for intraoperative consultation which yielded germ cell tumour, he underwent radical orchidectomy. A predominantly whitish cyst and a lobulated, variegated nodule were identified. Histology showed a mature cystic teratoma with a focus of infiltrative epithelioid cells containing eosinophilic cytoplasm and pleomorphic nuclei, invading ectatic vessel wall associated with fibrinoid change. These cells were positive for cytokeratin, human placental lactogen and inhibin, while negative for Melan-A, p63 and alpha-fetoprotein, consistent with placental site trophoblastic tumor (PSTT). The variegated nodule was a mixed germ cell tumour composed of embryonal carcinoma and immature teratoma. Aside from choriocarcinoma, primary trophoblastic tumors such as PSTT, which are derived from intermediate trophoblasts, are extremely rare in the testis. Aside from a case of pure testicular PSTT, 2 other cases have been described in association with germ cell tumour, of which one is a mature teratoma with PSTT that demonstrated gain of chromosome 12p. The other presented with PSTT in retroperitoneal recurrence of a testicular mixed germ cell tumour. We discussed the features of this tumour in the testis and important differentials in its diagnosis.
Singapore General Hospital, Pathology Department, 20 College Road, Academia, Level 10, Diagnostics Tower, Singapore 169856. leow.wei.qiang@sgh.com.sg.
Wei Qiang
WQ
Leow
Hwai Liang Alwin
HL
Loh
Lui Shiong
LS
Lee
Chin Hong Ronald
CH
Goh
D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D018193:Neoplasms, Complex and Mixed / Q000235:genetics / Q000473:pathology*; D009373:Neoplasms, Germ Cell and Embryonal / Q000235:genetics / Q000473:pathology*; D013724:Teratoma / Q000235:genetics / Q000473:pathology*; D013736:Testicular Neoplasms / Q000235:genetics / Q000473:pathology*; D014328:Trophoblastic Neoplasms / Q000235:genetics / Q000473:pathology*; D055815:Young Adult