Possible Ovarian and Peritoneal Carcinoma Presenting in a Mediastinal Lymph Node and Pleural Effusion: A Case Report and Review of the Literature

Ovarian carcinoma often doesn't show noticeable symptoms and is frequently diagnosed at an advanced stage. It is the most fatal cancer within the gynecologic system. Our understanding of ovarian pathology is limited, necessitating the use of multiple markers to accurately detect ovarian cancer, particularly when it presents abnormally, such as in pleural effusion or lymph nodes. A 45-year-old woman presented to the emergency room (ER) due to abdominal pain lasting for two weeks. A computed tomography (CT) scan revealed peritoneal carcinomatosis accompanied by ascites and calcification in the lymph nodes. The likely primary sources were determined to be mucinous adenocarcinomas from either the colon or ovary. Following the CT findings, a fine needle aspiration was conducted on a perigastric lymph node. Histopathology results indicated a "poorly differentiated carcinoma [with] malignant cells present." Subsequently, a PowerPort was inserted, and adjuvant chemotherapy commenced two days later, utilizing a combination of carboplatin, bevacizumab, and paclitaxel. Paracentesis was performed, yielding clear-yellow fluid. However, abdominal fullness gradually increased again after paracentesis. The patient began experiencing more intense abdominal pain, particularly in the left lower quadrant. Surgical exploration revealed widespread disease involvement throughout the intestines. Our patient exhibited an atypical manifestation of ovarian carcinoma, challenging its identification due to ectopic foci and the absence of many distinctly identifiable markers. Through comprehensive testing and a process of elimination, we successfully differentiated ovarian carcinoma from other potential cancers. The conclusive histopathological report, along with a markedly elevated CA-125 level, provided substantial support for the probable final diagnosis of ovarian carcinoma. Despite numerous advancements in staining and identification techniques, the diagnosis of ovarian carcinoma remains inadequately understood. Identifying ovarian carcinoma without clear visualization is often challenging, and further research is warranted to enhance our understanding of pathological methods. Moreover, there is a need to prioritize the development and exploration of ovarian carcinoma screening and testing methods to prevent delayed disease detection.