Improving Diagnosis of Pulmonary Mucormycosis: Leads From a Contemporary National Study of 114 Cases

Abstract

Background: Pulmonary mucormycosis (PM) is a life-threatening invasive mold infection. Diagnosis of mucormycosis is challenging and often delayed, resulting in higher mortality.

Research question: Are the disease presentation of PM and contribution of diagnosis tools influenced by the patient's underlying condition?

Study design and methods: All PM cases from six French teaching hospitals between 2008 and 2019 were retrospectively reviewed. Cases were defined according to updated European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria with the addition of diabetes and trauma as host factors and positive serum or tissue PCR as mycologic evidence. Thoracic CT scans were reviewed centrally.

Results: A total of 114 cases of PM were recorded, including 40% with disseminated forms. Main underlying conditions were hematologic malignancy (49%), allogeneic hematopoietic stem cell transplantation (21%), and solid organ transplantation (17%). When disseminated, main dissemination sites were the liver (48%), spleen (48%), brain (44%), and kidneys (37%). Radiologic presentation included consolidation (58%), pleural effusion (52%), reversed halo sign (26%), halo sign (24%), vascular abnormalities (26%), and cavity (23%). Serum quantitative polymerase chain reaction (qPCR) was positive in 42 (79%) of 53 patients and BAL in 46 (50%) of 96 patients. Results of transthoracic lung biopsy were diagnostic in 8 (73%) of 11 patients with noncontributive BAL. Overall 90-day mortality was 59%. Patients with neutropenia more frequently displayed an angioinvasive presentation, including reversed halo sign and disseminated disease (P < .05). Serum qPCR was more contributive in patients with neutropenia (91% vs 62%; P = .02), and BAL was more contributive in patients without neutropenia (69% vs 41%; P = .02). Serum qPCR was more frequently positive in patients with a > 3 cm main lesion (91% vs 62%; P = .02). Overall, positive qPCR was associated with an early diagnosis (P = .03) and treatment onset (P = .01).

Interpretation: Neutropenia and radiologic findings influence disease presentation and contribution of diagnostic tools during PM. Serum qPCR is more contributive in patients with neutropenia and BAL examination in patients without neutropenia. Results of lung biopsies are highly contributive in cases of noncontributive BAL.

Keywords: diagnostic strategy; mucormycosis serum PCR; pulmonary mucormycosis; radiologic presentation; underlying conditions.