Unusual Presentation of Non-Gestational Extragonadal Choriocarcinoma

Non-gestational choriocarcinoma is an extremely rare and highly aggressive malignant tumor that arises independent of gestational events, making less than 0.6% of all ovarian germ cell tumors. Unlike the more common gestational choriocarcinoma, which is associated with pregnancy, non-gestational choriocarcinoma originates from germ cells within the ovary. It accounts for a small fraction of ovarian malignancies and is often characterized by elevated levels of serum beta-human chorionic gonadotropin (β-HCG). The rarity and clinical overlap with other ovarian tumors pose significant diagnostic challenges, necessitating a thorough histopathological and immunohistochemical examination for accurate diagnosis. A 39-year-old female presented with a two-week history of right-sided migraine and general malaise, followed by a three-day onset of vision loss in the right eye. Initial evaluation in the emergency department included a chest X-ray, which revealed a 10 cm rounded opacity in the upper lobe of the left lung. A CT scan of the head showed a 4.5 cm rim-enhancing lesion in the left occipital lobe, along with a left middle cerebral artery (MCA) aneurysm. Notably, her serum β-HCG levels were significantly elevated at 5,642 mIU/mL despite the absence of intrauterine or extrauterine pregnancy on abdominal and pelvic ultrasound. Further workup included a CT thorax and MRI of the brain, which confirmed the isolated lung mass and left occipital lobe mass with no other sites of disease, leading to her transfer to the neurosurgery department. The patient underwent a left occipital craniotomy with tumor resection. Histopathological analysis confirmed the diagnosis of choriocarcinoma. Chromosomal analysis showed no evidence of the Y chromosome and confirmed the non-gestational origin of the choriocarcinoma. This case report discusses the non-specific presentation, radiological features, current treatment options, and potential safety strategies for managing this rare condition.