Cutaneous cryptococcal infection: Initial manifestation of acquired T-cell immunodeficiency due to malignant thymoma.

Background and purpose: Cryptococcosis is a known opportunistic infection. Thymomas are known to cause immune dysregulation. We describe an atypical case of cutaneous cryptococcosis in a patient with acquired T cell immunodeficiency that has been found to be secondary to a type B3 thymoma with progression to carcinoma.

Case report: A 63-year-old male presented with a chronic skin lesion confirmed as Cryptococcus neoformans on biopsy and an incidental mediastinal mass found during infectious work-up for the notable cluster of differentiation 4 (CD4)+ lymphopenia. This led to the diagnosis of a type B3 thymoma requiring resection. The cryptococcal lesion was treated successfully with azole therapy.

Conclusion: C. neoformans is an opportunistic infection rarely associated with isolated T cell immunodeficiency due to thymomas. A multidisciplinary approach and understanding of the pathogenicity of cryptococcus and the immunological effect of thymic dysfunction are paramount to diagnosis and treatment.