Gastrointestinal Stromal Tumor Masquerading As Acute Decompensated Heart Failure: A Challenging Diagnosis.

Gastrointestinal stromal tumors (GISTs) are rare lesions of the gastrointestinal tract that have a strong predisposition to the stomach and small intestine. We present a case of an 89-year-old female who initially presented to the emergency room with signs and symptoms of acute decompensated heart failure (HF) and was later discovered to have a 23-centimeter GIST in her abdominal cavity. This case emphasizes the implications of large intraperitoneal neoplasms and the unique constellation of symptoms they may present with.