Pulmonary mucormycosis: serial morphologic changes on computed tomography correlate with clinical and pathologic findings.

PURPOSE: To evaluate serial computed tomography (CT) findings of pulmonary mucormycosis correlated with peripheral blood absolute neutrophil count (ANC).
MATERIALS AND METHODS: Between February 1997 and June 2016, 20 immunocompromised patients (10 males, 10 females; mean age, 48.9 years) were histopathologically diagnosed as pulmonary mucormycosis. On initial (n=20) and follow-up (n=15) CT scans, the patterns of lung abnormalities and their changing features on follow-up scans were evaluated, and the pattern changes were correlated with ANC changes.
RESULTS: All patients were immunocompromised. On initial CT scans, nodule (≤3cm)/mass (>3cm) or consolidation with surrounding ground-glass opacity halo (18/20, 90%)) was the most common pattern. On follow-up CT, morphologic changes (13/15, 87%) could be seen and they included reversed halo (RH) sign, central necrosis, and air-crescent sign. Although all cases did not demonstrate the regular morphologic changes at the same timeline, various combinations of pattern change could be seen in all patients. Sequential morphologic changes were related with recovering of ANC in 13 of 15 patients.
CONCLUSION: Pulmonary mucormycosis most frequently presents as consolidation or nodule/mass with halo sign at CT. Morphologic changes into RH sign, central necrotic cavity or air-crescent sign occur with treatment and recovery of ANC. KEY POINTS: • Pulmonary mucormycosis showed various CT-morphology including CT halo sign • Pulmonary mucormycosis had trends of serial morphologic changes on follow-ups • Recovery of absolute neutrophil count changed CT-morphology of mucormycosis in immune-compromised patients.