Benign inclusions are foci of non-neoplastic ectopic tissue in lymph nodes. They are classified into three types: epithelial, nevomelanocytic and decidual. It is important to identify them for the differential diagnosis with lymph node metastases, particularly among patients who present proliferative benign lesions. In general, epithelial inclusions are presented inside lymph nodes as epithelial cysts or as numerous structures resembling ducts. The cells of these structures may originate from the cells of paramesonephricus ducts, salivary glands, breast tissue, thyroid follicles, squamous epithelium or mesothelium. Paramesonephricus -type inclusions are almost exclusively found in pelvic lymph nodes and, in appearance, they resemble the epithelium of the... |