Abstract Introduction Mucormycosis is a rare angioinvasive fungal infection with a mortality rate of 40–80%, depending on the site. Poorly controlled diabetes (36%) and hematologic malignancies (19%) are the leading risk factors. Although pulmonary mucormycosis is most often associated with hematologic malignancies, in prior case series, up to 50% of cases were in patients with diabetes. Pulmonary mucormycosis usually progresses rapidly, though some follow an indolent course that delays recognition. Case Report A 49-year-old man from Mexico with poorly controlled type 2 diabetes mellitus (HbA1c 14.7%) presented with a two-week history of cough, pleuritic chest pain, dyspnea, and eight-pound weight loss despite outpatient antibiotics. Examination revealed diminished breath sounds over the left lower lung field and multiple hyperpigmented skin plaques. Laboratory data showed leukocytosis (13.1 ×10³/µL), severe hyperglycemia (450 mg/dL), and elevated inflammatory markers (CRP 892 mg/L, ESR 120 mm/hr). Chest radiography showed left-lower-lobe consolidation, and CT chest revealed a 3.6 cm cavitary lesion. He was treated for presumed necrotizing pneumonia with vancomycin and piperacillin–tazobactam. A broad infectious workup, including cultures, Legionella and Streptococcus urinary antigens, Aspergillus assays, and endemic fungal serologies, was negative except for a positive QuantiFERON test. Due to poor sputum production and persistent fevers, bronchoscopy was performed, showing no endobronchial lesions. BAL was negative for AFB. The patient defervesced and WBC down-trended, so he was discharged with a plan to complete four weeks of amoxicillin–clavulanate for necrotizing pneumonia. Eleven days later, Rhizopus species grew from the BAL culture. The patient reported continued clinical improvement, so contamination was initially considered, but he was readmitted for further evaluation. Repeat CT demonstrated diffuse multifocal bilateral tree-in-bud and ground-glass opacities, confirming progression. Surgical resection was not pursued due to multifocal involvement. He was treated with liposomal amphotericin B and posaconazole; amphotericin was later stopped due to nephrotoxicity. On discharge, he continued posaconazole for two months before self-discontinuing. At five-month follow-up, he reported clinical improvement with improved imaging. Discussion We present a case of pulmonary mucormycosis with an indolent presentation in a 49-year-old male with uncontrolled diabetes. Although classically associated with hematologic malignancy, pulmonary disease is increasingly described in diabetics. Culture confirmation may be delayed, and transient clinical improvement can obscure progression. Imaging findings such as cavitation, ground-glass opacities, or the reversed-halo sign should prompt suspicion in diabetics unresponsive to antibiotics. Early recognition, antifungal therapy, and metabolic control remain essential to improving outcomes. This abstract is funded by: None
Sisalema et al. (Fri,) studied this question.