Cytopathological characteristics of angioimmunoblastic T-cell lymphoma diagnosed by fine needle aspiration

To analyse the cytopathological features of fine needle aspiration (FNA) in angioimmunoblastic T-cell lymphoma (AITL) diagnostics.Fine needle aspiration lymph node biopsy samples from 12 patients with AITL were collected at a single centre between January 2014 and December 2020. The clinical, cytological and histopathological characteristics were retrospectively analysed.Three male and six female patients with AITL who had a median onset age of 65 years (range 51-74 years) and a mean follow-up period of 29 months (range 12-47 months) were included. The FNA cytological and morphological analysis of the reactive lymph node background revealed diffusely distributed non-homogeneous mixed lymphocytes, including mature small lymphocytes, medium-sized lymphoid cells, immune cells, and plasma cells; some mixed eosinophils, macrophages, and an occasional mixture of visible and medium-sized lymphocytes and epithelioid cells were observed. Mitotically active lymphocytes and sporadic pigmented bodies were observed occasionally. An abnormal proliferation of follicular dendritic cells observed under the microscope is important for AITL diagnosis, and these cells are often distributed in a scattered pattern of small clusters with many nuclear morphologies. Branched capillaries are another important diagnostic clue. Two patients with AITL who achieved clinical remission after treatment experienced recurrence and were diagnosed using FNA and cell block immunohistochemistry.Fine needle aspiration provides clues for the diagnosis of AITL in special clinical situations, and cell block immunohistochemistry is worthy of further exploration.