High-Grade Serous Ovarian Carcinoma Presenting With Massive Pleural Effusion in the Absence of Ascites: A Case Report and Review of the Literature.

Pleural effusion as an initial presentation of malignancy poses significant diagnostic challenges, particularly when linked to gynecologic cancers. We discuss the case of a 53-year-old female who presented with progressive dyspnea and a massive right-sided pleural effusion. Cytological analysis of the pleural fluid revealed malignant cells and immunohistochemical staining confirmed high-grade serous carcinoma (HGSC) of ovarian origin. Remarkably, there was no evidence of peritoneal carcinomatosis, ascites, or ovarian mass. PET-CT identified additional metastatic foci in the cul-de-sac. The patient was treated with systemic chemotherapy using carboplatin and paclitaxel, complemented by palliative management for recurrent effusion. This report highlights the critical importance of a multidisciplinary approach integrating clinical, pathological, and imaging findings to address atypical presentations of ovarian cancer.