Abstract

Benign inclusions are defined as foci of non neoplastic ectopic tissues in lymph nodes encompassing various types of tissues. Benign epithelial inclusions have been reported in lymph nodes of various anatomical locations including head and neck, mediastinum, axilla, peritoneal, pelvic and inguinal regions. Epithelial inclusions can be divided into epithelial, nevomelanocytic and decidual. Further subtypes based on the tissue of origin include salivary gland tissue, thyroid tissue, squamous epithelial cells, breast tissue, mesothelial cells etc. The nature of tissue in heterotopic inclusions varies according to the location of the lymph nodes. The accurate diagnosis of these benign epithelial inclusions is of utmost clinical importance to prevent misinterpretation of this entity as malignant and hence save the patient from overzealous and inappropriate treatment. Hence, great importance should be given to detailed morphological evaluation of lymph nodes with epithelial inclusions in reaching at an accurate diagnosis. The cytological criteria favouring benign epithelial inclusions over metastatic carcinoma include a lack of significant nuclear atypia, pleomorphism and hyperchromasia. It is very important to create awareness of this rare entity among pathologists to prevent misdiagnosis or overdiagnosis of a malignant lesion.

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