Qiliang Liu, Mei Lei

Department of Pathology of Wuhan Pulmonary Hospital, Wuhan Tuberculosis Prevention and Control Institute, Wuhan, Hubei, 430030, People’s Republic of China

Correspondence: Mei Lei, Wuhan Pulmonary Hospital, Wuhan Tuberculosis Prevention and Control Institute, Wuhan, Hubei, 430030, People’s Republic of China, Email 912671267@qq.com

Introduction: Pulmonary Cryptococcosis (PC) is an invasive pulmonary fungal disease caused by cryptococcal infection, with diagnosis being challenging and prone to misdiagnosis. This research comprehensively analyzes the clinical, imaging, and pathological characteristics of PC, aiming to enhance diagnostic and therapeutic proficiency for PC.
Methods: Clinical data of 60 PC patients diagnosed in our hospital from January 2019 to June 2024 were retrospectively scrutinized.
Results: 60 patients were enrolled (40 males, 20 females), with an average age of 49.1± 13.3 years. Notably, 47 patients (78.3%) were 40 years old or older. 47 cases had chronic underlying diseases, including 2 AIDS patients. Respiratory symptoms were observed in 33 patients, with cough being the most common. Serum cryptococcal capsular antigen testing was conducted on 52 patients, revealing a diagnostic sensitivity of 44.2% (23/52). Imaging revealed predominant involvement of the right lower lung. A peripheral subpleural distribution pattern was observed in 28 cases (46.7%). Lesions exhibited diverse morphologies: solitary, multiple nodules/masses, patchy/consolidation shadows, and a mixed form of these. The mixed type was most prevalent, with 30 cases. Initially, 56 cases were misdiagnosed as tuberculosis, lung cancer or others prior to pathological confirmation. Histopathology showed granulomas and/or multinucleated giant cells in 57 cases. Cryptococcal yeast cells phagocytosed within these cells appeared as colorless, transparent, round or oval structures (4– 15 um in diameter) with a refractile clear halo on HE staining, while methenamine silver and PAS staining highlighted them as black or bright-red, facilitating diagnosis. Eleven patients underwent surgical resection followed by fluconazole therapy, and 45 received fluconazole or itraconazole therapy, with most achieving stable outcomes.
Conclusion: PC predominantly impacts men over 40 with chronic comorbidities. Serological tests and imaging may indicate PC, yet a definitive diagnosis necessitates lung biopsy or surgical pathology. Antifungal drugs and/or surgery typically resulted in a favorable prognosis.

Keywords: pulmonary cryptococcosis, pathology, diagnosis, tuberculosis