Papillary cystadenoma lymphomatosum (Warthin's tumor) is generally considered to be a benign tumor. However, a few well-documented cases of malignant transformation have been reported. In each case, the patient had received radiotherapy to the neck region where the tumor later developed.
This paper reports a case of malignant transformation of a papillary cystadenoma lymphomatosum (PCL) in a patient who had not received radiotherapy. Light and electron microscopy documented this transformation and clearly identified the malignant portion of the tumor as having its origin in a benign PCL.
The literature is reviewed and a discussion of pathology presented.