An Uncertain Cardiac Mass: A Case of Whipple's Disease.

Whipple's disease is a rare multisystem infectious disorder with a heterogeneous clinical presentation that frequently leads to delayed diagnosis. Relapses may occur even years after apparent remission. We report a 54-year-old man with a previous diagnosis of Whipple's disease who presented with fatigue, weight loss, anemia, and recurrent gastrointestinal symptoms. Echocardiography showed a persistent aortic valve mass with progressive regurgitation in the setting of repeatedly negative blood cultures and minimal systemic inflammatory response. Upper gastrointestinal endoscopy with duodenal biopsies revealed periodic acid-Schiff-positive macrophages, and real-time polymerase chain reaction confirmed Tropheryma (T.) whipplei in duodenal tissue. The patient received intravenous ceftriaxone followed by oral doxycycline plus hydroxychloroquine and underwent mechanical aortic valve replacement; polymerase chain reaction of the excised valve was also positive for T. whipplei. This case emphasizes the need to consider T. whipplei in indolent, culture-negative endocarditis and highlights the role of molecular testing and multidisciplinary management.