Cryptococcosis in patients with myasthenia gravis: clinical characteristics and management strategy.

Background: Cryptococcosis, while well-documented in immunocompromised hosts, remains a rare complication in myasthenia gravis (MG) patients undergoing immunosuppressive therapy. Methods: We reported three cases of cryptococcal infection in MG patients diagnosed via cryptococcal antigen (CrAg) testing and/or histopathology, coupled with a comprehensive literature review of 14 additional cases that highlights the diagnostic and therapeutic challenges in this population. We also explored potential immunodeficiency by whole-exome sequencing (WES). Results: The comibined cohort (median age 57.1 years) demonstrated predominant central nervous system (52.9%), pulmonary (47.1%), and cutaneous (23.5%) involvement, with disseminated disease correlating with markedly decreased CD4+ T cells counts. Diagnostic complexity arose from imaging findings mimicking malignancies. A heterozygous FAS mutation (p.S19L) was identified by WES in one of our patients; however, its association with cryptococcal infection remains unclear. Management required tailored antifungal regimens (amphotericin B, fluconazole, flucytosine) and careful therapeutic drug monitoring to address immunosuppressant interactions. Four patients received surgical management targeting the local lesions. Most cases achieved clinical resolution. Conclusion: The management of cryptococcal infection in patients with MG poses significant challenges in the context of underlying immune dysfunction and the use of immunosuppressive therapy. Within this complex clinical scenario, early recognition, multidisciplinary care, and individualized treatment strategies are paramount. They underscore the need for heightened clinical vigilance and further research to optimize outcomes in this vulnerable patient population.