Lung infection due to opportunistic fungus, Phialemonium obovatum, in a bone marrow transplant recipient: an emerging infection with fungemia and Crohn disease–like involvement of the gastrointestinal tract

Abstract

We report the first case of Phialemonium obovatum fungemia with subsequent caseating granulomatas in the lung and Crohn disease-like involvement of the gastrointestinal tract in a bone marrow transplant recipient. This phaeoid fungus has been rarely described as an opportunistic infection in immunosuppressed patients. The patient was diagnosed with chronic myelogenous leukemia and underwent subsequent peripheral bone marrow transplant. After 6 months, he developed graft-versus-host disease of the skin and liver with fever and severe diarrhea. Fecal bacterial cultures and cytomegalovirus serologies were negative. Computed tomographic scan showed a peripheral pulmonary mass. A lung wedge biopsy of the lesion showed septate branching hyphae (4-5 microm in diameter) with terminal globular structures (10 microm in diameter). The hyphae were similar in width to that of an Aspergillus species but had a more moniliform appearance. Blood cultures grew a pure culture of P. obovatum. He was treated with amphotericin B and itraconazole for 6 months without remission of the diarrhea. Biopsies of the stomach, colon, and rectum showed granulomatous inflammation with marked crypt distortion simulating Crohn disease. In retrospect, the fungus was found to be resistant to both of the aforementioned drugs and susceptible to voriconazole and posaconazole. The gastrointestinal findings raise the possibility of further dissemination of a partially treated Phialemonium infection.