Tuberculous lymphadenitis is a chronic specific granulomatous inflammation with caseation necrosis. The characteristic morphological element is the tuberculous granuloma (caseating tubercule) : giant multinucleated cells (Langhans cells), surrounded by epithelioid cells aggregates, T cell lymphocytes and few fibroblasts. Granulomatous tubercules evolve to central caseous necrosis and tend to become confluent, replacing the lymphoid tissue.
Epithelioid histiocytes (Epithelioid cells) are activated macrophages resembling epithelial cells. Structurally, they are elongated, with finely granular, pale eosinophilic (pink) cytoplasm, and central, ovoid nuclei (oval or elongate), which are less dense than that of a lymphocyte. They have indistinct shape and often appear to merge into one another, forming aggregates known as giant cells. Epithelioid cells are central in the formation of granulomas