Angioimmunoblastic T‐cell lymphoma masquerading as granulomatous lymphadenitis: Fine needle aspiration cytology, clinical and radiology correlation

Abstract

Fine needle aspiration (FNA) is a minimally invasive technique used in the initial diagnosis of superficial lesions, including lymphadenopathy. Its benefit in lymph node pathology, however, is highly variable, especially in heterogeneous lymphoproliferative disorders like angioimmunoblastic T‐cell lymphoma (AITL). AITL is an aggressive hematopoietic malignancy, histologically characterized by medium‐sized neoplastic cells, high endothelial venule proliferations, and a heterogeneous hematolymphoid background. Diagnostic difficulty arises at lymph node FNA, where cytology yields nonspecific polymorphous collections of medium‐sized lymphocytes, hematolymphoid cells, dendritic cell‐lymphoid complexes, and lymphoid tissue fragments with transgressing blood vessels; findings mimicking reactive lymphadenopathy. We present a case of a 62‐year‐old male who presented with cervical lymphadenopathy. Neck level II lymph node FNA revealed granulomatous inflammation. A cell block was prepared for additional infectious studies but was non‐contributory due to lack of material. Flow cytometry showed no evidence of non‐Hodgkin lymphoma. Excisional biopsy revealed lymph node effacement by a T‐cell lymphoproliferative disorder consistent with AITL. This case contributes to the paucity of literature regarding the cytologic features of AITL observed at FNA, and becomes the premier case to emphasize the addition of granulomatous features. Despite the aggressive nature of this entity, cases are frequently misdiagnosed as reactive on initial evaluation resulting in delay of treatment. This report serves to raise suspicion of AITL and other polymorphic cellular lymphomas in the setting of reactive granulomatous cytomorphology, thus prompting histological examination of tissue biopsy, expediting treatment, and ultimately providing potential improvement to the current prognosis.