Friday, July 3, 2015
I got a biopsy done on a mouth lesion by a dentist. He thought it was a cyst and opened it to drain it, but found some tissue pellets that he thought needed to be biopsied. I got the biopsy results back and it said "suggestive of pleomorphic adenoma" with a note that said they couldn`t rule out adenocarcinoma because there wasn`t a sample that showed ht interface between the lesion and healthy tissue. I went to an oral surgeon and he seems to think it is a PA too, but wants to redo the biopsy. Just for my peace of mind, how confident would you say an oral pathologist issuing this diagnosis would be? What is the rate of assuredness inidicated by "suggestive of"?
This is an issue that oral pathologists deal with occasionally - that is, a biopsy sample from a salivary gland tumor that is fragmented, making interpretation more challenging. The cells of pleomorphic adenomas often have certain microscopic features that are characteristic for that lesion. The difficulty arises because sometimes we see low-grade (not very aggressive) salivary gland malignancies ("cancer") that can mimic pleomorphic adenoma microscopically.
The best way to tell the benign from the malignant tumor is to obtain another biopsy sample - basically a wedge of the tumor that includes some of the normal tissue. If it is a malignancy, it would show cells invading the normal tissue, while the pleomorphic adenoma will usually not show such an aggressive pattern. The odds are good that the oral pathologist is correct with his or her initial assessment, but every now and then we encounter a tumor that surprises us when we look at the final biopsy sample.
For that reason, you should have the second biopsy procedure done, and hopefully it will confirm the oral pathologist's diagnosis.
Carl M Allen, DDS, MSD
Professor Emeritus of Oral Pathology
College of Dentistry
The Ohio State University