Peritoneal Carcinoma Unveiling a Hidden Threat: A Case of Malignant Pericardial Effusion.

Malignant pericardial effusion (MPE) is a slowly progressive and potentially clinically silent condition. Pericardial effusion can arise in oncology patients due to several factors, including disease spreading directly or metastatically, anticancer therapy side effects, or both. Solid and hematological malignancy metastasis more frequently involves the pericardium than primary tumors, with lung cancer being the most common metastatic tumor to involve the pericardium. While 5%-20% of all patients with metastatic neoplasms have pericardial involvement, MPE rarely appears with hemodynamic instability. Occasionally, MPE constitutes the initial manifestation of an underlying malignancy. Diagnosis and treatment require a multidisciplinary approach and a high degree of clinical suspicion. We present a case of a 59-year-old female with a history of peritoneal carcinoma who presented with persistent dyspnea on exertion following an episode of pneumonia that was treated with antibiotics. Physical examination and bedside point-of-care ultrasound (POCUS) revealed fluid in the pericardial sac. The cytological examination of the fluid revealed it to be of malignant origin, resulting from metastasis from gynecologic adenocarcinoma. Pericardiocentesis was done, and symptoms improved after fluid drainage.