TUMOR-ASSOCIATED LYMPHOID PROLIFERATION IN THE PAROTID-GLAND - A POTENTIAL DIAGNOSTIC PITFALL

A substantial proportion of neoplastic and nonneoplastic parotid disea ses have a prominent lymphoid component. The lymphoid element in lesio ns such as papillary cystadenoma lymphomatosum, sebaceous lymphadenoma , and lymphoepithelial carcinoma are readily recognized as a required diagnostic element. However when other types of benign and malignant s alivary gland neoplasms demonstrate tumor-associated lymphoid prolifer ation, the tumor may be either misclassified or misinterpreted as meta static disease. Examples of primary benign and malignant parotid neopl asms exhibiting tumor-associated lymphoid proliferation are documented and illustrated. Other parotid lesions that may have a lymphoid eleme nt include sialadenitis, cysts with associated lymphoid tissue, parenc hymal neoplasms with an expected lymphoid component or those that aris e within an intraparotid lymph node, autoimmune disease, malignant lym phoma, and metastatic disease. An approach to recognition and separati on of these entities is discussed.