Metastatic choriocarcinoma of the kidney in the absence of existing primary uterine tumor: A rare presentation.

Gestational choriocarcinomas are malignant neoplasms generally arising in the uterus in women of childbearing age. These are aggressive tumors with a high incidence of metastasis to vascular organs such as the lung, liver, and brain. Renal metastasis is extremely rare with low incidence rate and very few cases have been reported in literature. Hereby, we report a rare case of metastatic choriocarcinoma to the kidney in a 29-year-old female 10 years after resection of a hydatidiform mole. The histopathological diagnosis was made on a nephrectomy specimen. Pelvic and abdominal scan did not show any abnormal radiological findings. She was started on first-line chemotherapy and showed a complete response. In conclusion, gestational or primary nongestational choriocarcinomas should always be considered as a differential diagnosis in young females of reproductive age group presenting with flank abdominal pain, unexplained hematuria, and atypical renal tumor histology.