INFLAMMATORY PSEUDOTUMOR OF LYMPH-NODES

Aim - To describe the clinical, histological and immunohistochemical f eatures in four cases of an uncommon benign lymph node lesion which ma y mimic a neoplastic process. Methods - Four cases of inflammatory pse udotumour of lymph nodes were studied using conventional staining (hae matoxylin and eosin, PAS, Gordon and Sweets reticulin stain, and the Z iehl-Neelsen stain) and with immunohistochemical techniques using a va riety of antibodies (CD3, L26, CD15, CD21, CD30, KP1, MAC 387, vimenti n, alpha SMA, HHF-35, D33, CD34, and S100). Results - The lesion compr ises a proliferation of spindle cells expanding the connective tissue framework of lymph nodes and is associated with a plasma cell and smal l lymphocyte infiltrate. There are variable numbers of macrophages, ne utrophils and eosinophils, and varying degrees of fibrosis. Vascular c hanges are common but vary in degree and type. Conclusions - Inflammat ory pseudotumour of lymph nodes is an uncommon benign reaction pattern which may be misdiagnosed as a neoplastic or even a malignant process . Increased awareness of its histological features should help prevent such misdiagnoses.