Diagnostic approach to ovarian cancer presenting with recurrent seizures: a case report

Ovarian cancer is the second most common cause of death among gynecologic malignancies. Ovarian cancer is generally diagnosed at an advanced stage due to nonspecific signs and symptoms. This case report presents a 50-yearold woman with an ovarian tumor suggestive of malignancy, diagnosed based on imaging findings and an elevated tumor marker CA 125. The gold standard examination, histopathological biopsy, could not be performed. The patient presented with abdominal distension, abdominal pain, and recurrent shortnessof breath. Chest X-ray revealed recurrent pleural effusion. Abdominal CT scan demonstrated ascites accompanied by a solid ovarian mass suggestive of malignancy and a significant elevation of CA 125 tumor marker with a CA 125/CEA ratio of 622/1.7. However, cytological examination of the ascitic fluiddid not indicate malignancy. The patient underwent repeated evacuation of pleural effusion and ascitic fluid. Biopsy or surgical intervention could not be performed; therefore, histopathological confirmation of the tumor was not possible. Recurrent seizures were observed in this patient, with brain MRI showing gliosis and cystic encephalomalacia. The patient received six cycles of neoadjuvant chemotherapy with carboplatin and paclitaxel, with the last dose administered on June 21, 2025. On June 29, 2025, however, the patient passed away after one day of hospitalization, the primary presenting complaint being decreased consciousness. The gold standard for diagnosing ovarian cancer is histopathological biopsy. If a histopathological biopsy cannot be performed,a combination of imaging examinations, cytology of ascitic fluid or pleural effusion, and an elevated CA 125:CEA ratio greater than 25 may be used. In this patient, ascitic fluid cytology yielded negative results, possibly due to inadequate sampling. Recurrent seizures and decreased consciousness in this patient may have been caused by gliosis, sequelae of stroke, or possible metastasis, thereby necessitating additional diagnostic modalities. Establishing a diagnosis of ovarian cancer poses unique challenges. A combination of imaging, tumor markers, and fluid cytology can serve as valuable modalities to guide the diagnosis of ovarian cancer when histopathological biopsy cannot be performed.