Peripheral T-cell lymphoma-NOS presenting with cavitary lung lesions mimicking invasive aspergillosis.

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), is a rare subtype of non-Hodgkin lymphoma that frequently presents with multiorgan involvement. We report a diagnostically challenging case of a female in her late 40s presenting with otomastoiditis, brain abscess and bilateral cavitary lung lesions. A positive serum galactomannan led to empiric antifungal therapy for presumed disseminated aspergillosis. However, tissue biopsies were negative for infection, and histopathology ultimately confirmed PTCL-NOS. This case highlights a rare presentation of PTCL-NOS, involving both the lungs and central nervous system, mimicking invasive fungal disease.