Adenocarcinoma of unknown primary presenting with congestive heart failure in a middle-aged Ethiopian woman: a case report.

Background: Heart failure is a rare manifestation of metastatic disease of the carcinoma of an unknown primary, malignancy that requires extensive work-up to identify the primary site. Initial consideration of rare etiologies in patients presented with a common clinical syndrome is challenging.

Case presentation: A 35-year-old Black woman presented with shortness of breath at rest, orthopnea, paroxysmal nocturnal dyspnea, chest pain, a blood-tinged productive cough, and fever for 2 weeks. She also had progressive body swelling, easy fatigability, loss of appetite, and abdominal pain during the same week's duration. Body imaging revealed large pleural and pericardial effusions, metastatic liver lesions, and bilateral pulmonary vascular segmental and subsegmental filling defects. Pericardial and pleural fluid cytology suggest malignant effusion. Liver lesions and core needle biopsy indicated adenocarcinoma of unknown origin, and the carcinoembryonic antigen level also increased significantly.

Conclusion: Carcinoma of unknown primary origin commonly presents in an advanced stage and is often accompanied by clinical features of site metastasis. This case highlights heart failure as an unusual first manifestation of adenocarcinoma with an unknown primary origin.