Post molar choriocarcinoma with solitary renal metastasis in the absence of primary uterine tumor: a case report and review of the literature.

BACKGROUND: Choriocarcinoma is a rare and highly malignant form of gestational trophoblastic disease that may develop following pregnancy, abortion, or a hydatiform mole. Renal metastatic involvement by post molar choriocarcinoma is even rarer. In this case report, we describe a unique case of post molar choriocarcinoma with a solitary renal metastasis in the absence of a primary uterine tumor and metastases in other sites, which presented with urological symptoms and spontaneous renal hemorrhage.

CASE PRESENTATION: A 41-year-old Persian woman with history of complete hydatiform mole presented with severe flank pain, nausea, vomiting, gross hematuria, and vaginal bleeding. Laboratory tests demonstrated a serum beta human chorionic gonadotropin hormone level of 60,000 mIU/mL. Imaging studies showed a lesion at the lower pole of the left kidney with active bleeding surrounded by hematoma, as well as an empty uterine cavity. Additionally, bilateral pleural effusion was detected without any lesion within the lungs. Subsequently, the patient underwent laparotomy, partial nephrectomy, and left para-ovarian cystectomy. Endometrial curettage was also carried out. The histopathology report revealed choriocarcinoma renal metastasis with high expression of beta human chorionic gonadotropin, cytokeratin 7, and Ki 67. Moreover, there were no malignant cells in the endometrial curettage specimens, and a corpus luteum cyst was found within the para-ovarian cyst. Further investigations revealed that the pleural effusion was free of malignant cells, and there was no evidence of metastatic lesions in the brain. As a result, the patient was referred to the oncology department to receive chemotherapy, and the beta human chorionic gonadotropin levels dropped to 5 mIU/mL after receiving courses of a standard regimen of etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine/oncovin over 3 weeks. Finally, monthly measurements of beta human chorionic gonadotropin levels for 6 months indicated that levels have constantly remained within normal ranges, showing no evidence of recurrence or new metastasis.

CONCLUSIONS: Urological symptoms such as hematuria or spontaneous renal hemorrhage might be the only presentation of post molar choriocarcinoma with renal involvement. Thus, it can be beneficial to measure serum beta human chorionic gonadotropin levels among females of childbearing age who present with unexplained urological symptoms, especially if there is a history of prior hydatiform mole.