Lymph Node Cytology: Morphology and Beyond

Abstract

Fine needle aspiration cytology (FNAC), being minimally invasive, rapid, cost-effective provides a valuable first-line diagnostic tool in the evaluation of lymphadenopathies both benign and malignant. Various ancillary techniques namely immunocytochemistry, flow cytometry, cell blocks, and molecular studies further improve the diagnostic accuracy of FNACs. Targeted FNAC under ultrasound guidance optimizes cellular yield in palpable and non-palpable lymphadenopathies. FNAC proves to be indispensable at establishing tissue diagnosis in cases when surgical excision is unfeasible, as in elderly patients with comorbidities or in metastatic settings. Nevertheless, lymph node FNAC represents a daunting task owing to the multitude of benign and malignant causes of lymphadenopathy. To aid categorization and better communication to the clinician, an emphasis on classification and reporting of lymph node cytopathology using Sydney system is laid upon.