Pulmonary mucormycosis presenting as nonresolving pneumonia in a patient with diabetes mellitus.

Zygomycosis refers to a group of disorders caused by filamentous fungi in the class Zygomycetes. This class is subdivided into 2 orders, Mucorales and Entomophthorales, both implicated in human disease. The majority of human infections are caused by fungi in the Mucorales order; hence, the terms zygomycosis and mucormycosis are often used interchangeably. The human population is most frequently affected by the Mucor, Rhizopus, Absidia, and Chlamydoconidia species, with Mucor being the most common. Members of the Mucorales order are saprophytic organisms that are ubiquitous in nature and enter the human body through the respiratory tract or non-intact skin. They mostly affect people with hematological malignancy, hematopoietic stem cell transplantation, prolonged neutropenia, diabetes mellitus, and trauma. Other immunocompromised patients at risk include those using corticosteroids or desferoxamine, undergoing solid organ transplantation or long-term voriconazole prophylaxis, or with iron overload.1,2 These fungi are highly vasotropic, with a propensity to cause thrombosis and tissue necrosis, and they are associated with very high mortality. Although most fungal infections, including mucormycosis, are acquired via inhalation, endobronchial manifestation is rare, and the usual presentation is either pulmonary or systemic disease. Among the endobronchial fungal infections, Aspergillus subspecies are the most common, and endobronchial mucormycosis (EBM) is still uncommon. The majority of endobronchial fungal infections occur in association with systemic dissemination in immunocompromised hosts.3 Herein, we report a case of isolated pulmonary mucormycosis with endobronchial involvement presenting as nonresolving pneumonia in a diabetic patient who was successfully managed with medical therapy.