Postmolar 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 high malignant type of gestational trophoblastic disease (GTD) that occurs after pregnancies, abortions, or hydatiform moles and seldom metastasizes to the kidneys. Postmolar choriocarcinoma with renal metastasis is also scarce and was not frequently described. Here, we depicted the first case of postmolar choriocarcinoma with solitary kidney metastasis presenting with spontaneous renal hemorrhage (SRH) in the absence of a primary uterine tumor. Case presentation: A 41-year-old female patient with a history of complete molar pregnancy was evaluated due to severe flank pain, nausea/vomiting, gross hematuria, and vaginal bleeding in the last three weeks. The evaluations demonstrated bilateral pleural effusion without any lesion within the lungs, an empty uterine cavity, and a left kidney lower pole lesion with active bleeding surrounded by hematoma, alongside a serum β-hCG level of 60,000 mIU/mL. According to these findings, laparotomy exploration was planned and ended with a partial nephrectomy, para ovarian cystectomy. In addition, endometrial curettage was performed. The histopathology results revealed choriocarcinoma renal metastasis with high expression of β-hCG, cytokeratin, cytokeratin7, and KI67. In addition, a corpus luteum cyst was found within the left ovarian cyst, and endometrial curettage showed a progestin agent effect without malignant cells. Moreover, the brain, liver, and adrenal glands were not involved with metastases, and the pleural effusion fluid was free of malignant cells. Finally, the patient was referred to the oncology department to receive chemotherapy, and the β-hCG level dropped to 5 mIU/mL after receiving courses of a standard EMA-CO regimen (etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine/oncovin) over three weeks. Conclusions: : Postmolar metastatic choriocarcinoma might present only urologic symptoms, such as hematuria and SRH, due to metastatic renal involvement. Indeed, considering choriocarcinoma and evaluating the serum β-hCG level among childbearing-aged females with unexplained urological symptoms could be advantageous, particularly when a previous molar pregnancy exists.