PT - JOURNAL ARTICLE AU - Jung-In Choi AU - Alice S Chang AU - Richard C Cook AU - Christopher B Fordyce TI - <em>Histoplasma capsulatum</em> culture-negative prosthetic valve endocarditis presenting as a cystic mass AID - 10.1136/bcr-2021-244914 DP - 2022 Feb 01 TA - BMJ Case Reports PG - e244914 VI - 15 IP - 2 4099 - http://casereports.bmj.com/content/15/2/e244914.short 4100 - http://casereports.bmj.com/content/15/2/e244914.full SO - BMJ Case Reports2022 Feb 01; 15 AB - A 58-year-old immunocompetent patient with previous prosthetic valve presented with chest pain, constitutional symptoms and septic shock. Blood cultures and transthoracic echocardiogram were negative, but the patient was initiated on broad spectrum antibiotics due to high clinical suspicions of infective endocarditis. The patient received a transoesophageal echocardiogram revealing a cystic bioprosthetic valve lesion. Culture-negative endocarditis workup identified active disseminated histoplasmosis with likely Histoplasma endocarditis. A multidisciplinary discussion was held, and the patient was deemed high-risk for a third re-do open heart surgery. He was treated medically with anti-fungal treatment with good clinical recovery.