A58-year-old man presented with a 1-month history of persistent nausea, vomiting, diarrhoea and fevers. He also reported worsening shortness of breath, lower extremity swelling, and a 4.5 kg weight loss. He was febrile and hypotensive, with pedal oedema and a soft diastolic murmur over the mitral area.

A white cell count and chest x-ray were normal. A transthoracic echocardiogram, performed to assess cardiac function, showed a large, highly mobile left atrial mass prolapsing into the left ventricle (Box, A [arrowed]).

At urgent surgery, an 8 cm left atrial myxoma arising from the interatrial septum was resected (Box, B). Histopathological examination showed dense colonies of yeast. Histoplasma capsulatum was grown from blood cultures and cultures of the surgical specimen (Box, C). HIV testing was negative. The patient made a full recovery after completing antifungal therapy.

Infected left atrial myxoma is rare. We know of only one other reported case in which Histoplasma was the infective agent.1

A: Transthoracic echocardiogram

B: Surgical specimen

C: Microscopic view of Histoplasma capsulatum (Gomori methenamine silver stain)