<prompt> Papillary cystadenoma lymphomatosum is otherwise called:Pleomorphic adenomaWarthins tumourMucoepidermoid carcinomaMedullary carcinoma  <response>: Ans: b Warthins tumour Ref: Bailey love, 23th ed,p. 1659;WARTHINS TUMOUR It is the second most common benign tumour of the parotid gland. 1 st is pleomorphic adenoma It consists of both epithelial and lymphoid elements and is also known as adenolymphoma. Probably arises from parotid tissue trapped in lymph nodes within parotid gland Also called papillary cystadenoma lymphomatosum . Tumour arises only in parotid gland. Almost always arises in lower portion of the parotid gland overlying the angle of mandible Common in males. Age - 5th to 7th decade. Assosciation is seen with smoking. Bilateral in 10 cases. Its well encapsulated, extremely slow growing tumour, never turns malignant.INVESTIGATIONPeculiar feature is that it shows a hot spot in 99m - Tc -pertechnate scan. 