Nocardia empyema in an immunocompromised host: A case report.

Patients with myeloproliferative disorders such as primary myelofibrosis are at an increased risk of opportunistic infections including Nocardia pneumonia. Nocardia can become disseminated with the central nervous system being the primary site affected although any organ system can be involved. Here we present a case of Nocardia empyema, a rare and sparsely documented location of infection, in a post matched unrelated donor hematopoietic cell transplant patient. Further complicating this case was the presence of fungal pneumonia in the right lower lobe that led to delayed diagnosis of Nocardia pneumonia and empyema as non-resolving nodular opacities were thought to be worsening fungal pneumonia. This case highlights the difficulties in diagnosing Nocardia infections, the limitations of our diagnostic tools, the atypical presentation of empyema in an immunocompromised host, and Hickam's dictum; the idea that a patient can have multiple diagnoses occurring simultaneously.