Pulmonary fungus ball caused by Penicillium capsulatum in a patient with type 2 diabetes: a case report

Background: Following the recent transfer of all accepted species of Penicillium subgenus Biverticillium to Talaromyces (including Talaromyces marneffei, formerly Penicillium marneffei), Penicillium species are becoming increasingly rare causal agents of invasive infections. Herein, we present a report of a type 2 diabetes patient with a fungus ball in the respiratory tract caused by Penicillium capsulatum. Case presentation: A 56-year-old Chinese female gardener with a 5-year history of type 2 diabetes presented at the Shanghai Changzheng Hospital with fever, a cough producing yellow-white sputum, and fatigue. The therapeutic effect of cefoxitin was poor. An HIV test was negative, but the beta-D-glucan test was positive (459.3 pg/ml). Chest radiography revealed a cavitary lesion in the left upper lobe, and a CT scan showed globate cavities with a radiopaque, gravity-dependent ball. The histopathologic features of the tissue after haematoxylin-eosin staining showed septate hyphae. The fungus was isolated from the gravity-dependent ball and identified as Penicillium capsulatum based on the morphological analysis of microscopic and macroscopic features and on ribosomal internal transcribed spacer sequencing. After surgery, the patient was cured with a sequential treatment of fluconazole 400 mg per day for 90 days and caspofungin 70 mg per day for 14 days. Conclusions: Although the prognosis is often satisfactory, clinicians, mycologists and epidemiologists should be aware of the possibility of infection by this uncommon fungal pathogen in diabetes patients, since it may cause severe invasive infections in immunocompromised hosts such as diabetes and AIDS patients.