Primary malignant teratoma of the kidney: a rare case report and literature review.

Teratomas originate from pluripotent cells and can differentiate along one or more embryonic germ lines. Renal teratoma is infrequent and malignant renal teratoma is even rarer. Experience in the diagnosis and treatment of this uncommon malignancy is seriously limited. In this report, we described the case of a 64-year-old female who complained of right flank pain for 4 months. Computed tomography (CT) revealed a hypodense mass (50 mm in maximum diameter) with slow contrast enhancement and obscure boundary located in the lower pole of the right kidney. CT also showed multiple retroperitoneal lymphadenectasis. Retroperitoneal laparoscopic right radical nephrectomy along with regional lymphadenectomy was successfully performed, and postoperative pathological examination confirmed malignant teratoma of the kidney. After surgery, the patient received adjuvant chemotherapy with BEP (bleomycin, etoposide, and cisplatin) protocol. At the 6-month follow-up, pulmonary and liver metastases were discovered by CT and the patient refused any further treatment. Unfortunately, she died at 16 months postoperatively. Although primary renal malignant teratoma is extremely rare, this kind of tumor should be taken into consideration. Currently, there is no therapeutic standard consensus for this disease and the prognosis remains unclear. Early detection and surgical intervention is critical, and more research on postoperative adjuvant therapy should be performed.