Papillary cystadenoma lymphomatosum /Wahin's tumor/Adenolymphoma Exclusively seen in parotid gland Derived from salivary tissue inclusion in lymph node More common in males Associated with smoking Only tumor to show hot spot on TC99m-Peecnate Histopathology Papillary cystic pattern lined with columnar oncocytes and cuboidal cells with marked lymphoid component. Lined by a double layer of neoplastic epithelial cells resting on a dense lymphoid stroma sometimes bearing germinal centers =Mikulicz's disease involves chronic inflammation and swelling of the salivary glands, which is benign and usually painless