A case of allergic bronchopulmonary mycosis caused by Schizophyllum commune with clamp connections on gram stained images

Abstract

We encountered a suspected case of allergic bronchopulmonary mycosis (ABPM) caused by Schizophyllum commune. The patient, a woman in her 50s with a history of chronic cough, underwent a chest X-ray, which revealed infiltration in the right upper and middle lung fields. She was referred to our hospital for further assessment and treatment. Blood analysis indicated elevated eosinophil counts and serum total IgE levels. A chest CT scan revealed central bronchiectasis and a hyperabsorbable mucus plug, leading to the suspicion of ABPM. Consequently, the patient was admitted for a bronchoscopy. Gram-stained images of bronchoalveolar lavage fluid showed characteristic features of S. commune, including clamp connections and hyphal spicules at the septum of the fungus. Subsequent cultures of Sabouraud Dextrose CG agar medium showed the formation of white, cotton-wool-like colonies after 72 h of incubation. The cellophane tape method confirmed the presence of clamp connections and spicules. Additionally, the basidiocarp was observed after 10 days of incubation. The findings from the mass spectrometry and genetic analysis revealed the presence of S. commune. Treatment with itraconazole and prednisolone resulted in no recurrence. The results of genetic analysis and mass spectrometry were consistent, and identification by mass spectrometry was useful. When assessing specimens from patients suspected of ABPM, consideration should be given to S. commune in addition Aspergillus spp. Morphological characteristics of the mycelium should be meticulously observed under low magnification of the microscope when examining Gram-stained specimens.