B72-18 Atypical Radiographic Presentation of Cryptococcus Pneumonia in an Immunocompetent Patient: A Case Report

Abstract Background Cryptococcus infection is usually an opportunistic disease in immunocompromised hosts, with high morbidity and mortality if untreated. Although uncommon, it can occur in immunocompetent individuals, where its nonspecific clinical and radiographic features, often mimicking other lesions, may delay diagnosis. Case A 78-year-old male, with heart failure and well-controlled diabetes, lifetime non-smoker and a former U.S. Marine, did serve in Okinawa for 2 years and has lived in Georgia rest of his life, presented with shortness of breath and cough. Chest X-ray showed pulmonary venous congestion, while CT revealed several thick-walled cavitary masses in the right upper and middle lobes. Diuretics were started for volume overload. Pulmonology was consulted, and biopsies were obtained. A CT one year earlier had showed smaller, fewer lesions with scattered ground-glass opacities. As shown in the image, the current cavitary lesions are new compared to 2024, when only small ground-glass nodules were present. During hospitalization, left heart catheterization revealed multivessel coronary artery disease, managed medically. Bronchoscopy with bronchoalveolar lavage showed 6% neutrophils; mycobacterium tuberculosis PCR, AFB stain, cultures, and cytology were all negative. Autoimmune testing was normal. Pathology from lung biopsy demonstrated findings consistent with Cryptococcus species, which prompted additional testing. Serum cryptococcal antigen was positive (initial titer 1:10, repeat 1:80). The patient was started on antifungal therapy and discharged home with outpatient follow-up. Discussion Pulmonary cryptococcosis most commonly affects immunocompromised hosts, and its radiographic presentation is highly variable, ranging from solitary or multiple nodules to mass-like consolidations. In this case, ground-glass opacities observed one year earlier; which is an atypical finding for cryptococcosis, unexpectedly progressed to cavitary lesions over the course of a year. Cavitary lesions are generally uncommon and often raise concern for alternative diagnoses such as tuberculosis, bacterial abscess, or malignancy. In our immunocompetent patient, the presence of multiple thick-walled cavities initially delayed consideration of a fungal etiology. The combination of progressive radiographic changes, exclusion of other infectious and autoimmune causes, and supportive biopsy findings with confirmatory serum cryptococcal antigen testing established in the diagnosis. While culture remains the gold standard, the concordant histopathologic and serologic evidence was sufficient to guide therapy. Conclusion This case emphasizes that cryptococcal pneumonia can present in cavitary lung lesions even in immunocompetent individuals. Clinicians should be aware of this uncommon manifestation to avoid misdiagnosis and ensure timely antifungal therapy. This abstract is funded by: None