Title : Unexpected pulmonary cryptococcosis in an immunocompetent individual: Case report and clinical analysis
Abstract:
Pulmonary cryptococcosis in immunocompetent individuals represents an underestimated diagnostic and therapeutic challenge, with growing relevance in clinical practice and global public health. Although historically associated with advanced immunosuppression—particularly HIV infection, solid organ transplantation, or prolonged corticosteroid use—cases are increasingly reported in patients without apparent risk factors, especially when related to Cryptococcus gattii, an emerging pathogen with a distinct epidemiological profile.
We present the case of a 73-year-old immunocompetent man from northern Mexico with a three- year history of chronic cough, significant weight loss, mild hemoptysis, and constitutional symptoms, initially interpreted as chronic inflammatory lung disease or possible pulmonary neoplasm. Chest CT revealed mediastinal lymphadenopathy and irregular consolidation, raising strong suspicion for malignancy. Bronchoscopy demonstrated grade III endobronchial infiltration, and multiple biopsies were required to establish the definitive diagnosis of pulmonary cryptococcosis. Serologies for HIV, HBV, HCV, and syphilis were negative, and the patient had no history of immunosuppression, recent travel, or high-risk exposures other than environmental contact with pigeons. CT imaging reported a lymph node conglomerate up to five centimeters in stations 2R and 4R, associated with an irregular area with air bronchogram in the right upper lobe. Bronchoscopy revealed grade II and III mucosal infiltrations, anthracotic mucosa, and extrinsic compression in segmental bronchi. Bronchial lavage cytology showed nonspecific inflammatory changes; however, endobronchial biopsies confirmed cryptococcosis, prompting antifungal therapy initiation.
This case highlights the global diagnostic challenge of pulmonary cryptococcosis in immunocompetent hosts. The disease can mimic tuberculosis, lung cancer, sarcoidosis, and other chronic granulomatous processes. Diagnostic delays are common due to nonspecific symptoms, variability in radiologic findings, and low clinical suspicion in non-endemic regions. In this patient, deep endobronchial biopsies were essential to differentiate fungal infection from malignancy given the extent of mucosal infiltration.
Therapeutic decision-making in this context is also complex. Although mild to moderate pulmonary cryptococcosis is typically managed with fluconazole, the persistence of hemoptysis, severe endobronchial involvement, and radiologic burden justified induction therapy with amphotericin B deoxycholate followed by high-dose fluconazole. This reflects the limitations of current guidelines— largely derived from immunocompromised populations—which offer limited precision for extensive endobronchial disease in immunocompetent hosts.
Beyond the individual case, this report addresses emerging epidemiological concerns: the geographic expansion of C. gattii as a primary pathogen, environmental changes altering fungal distribution, and the need to strengthen mycological surveillance in regions previously considered low risk. Clear opportunities exist to improve care through enhanced clinician awareness, early incorporation of fungal diagnostics in chronic pulmonary syndromes, standardization of therapeutic algorithms, and expansion of diagnostic capacity in resource-limited healthcare systems.
