PET/CT false-negative angioimmunoblastic T-cell lymphoma: a case report and literature review

Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma characterized by heterogeneous clinical and immunologic manifestations. We report a 65-year-old female whose morphologically abnormal superficial lymph nodes were fluoro-D-glucose (FDG)-negative on positron emission tomography/computed tomography (PET/CT), while deep mediastinal and hilar nodes were hypermetabolic. Initial biopsies of FDG-avid sites were non-diagnostic. Definitive diagnosis was ultimately achieved via excisional biopsy of a superficial node. This case underscores that AITL may exhibit PET/CT false-negativity, highlighting the need for integrating clinical, laboratory, flow cytometry, and histopathologic data to avoid diagnostic delays.