Polyp Adenomatous

Adenomatous Polyp of the Colon


The Common Vein Copyright 2008



An adenomatous polyp on the other hand is a benign neoplastic proliferation of mucosal cells with multifactoroal causes including a diet, obesity, smoking and genetics and the resulting adenoma is a pathological process that has a propensity to evolve into a malignant lesion over 10-15 years.  The lesion is diagnosed histologically after removal at colonoscopy, and is thus coincidentally treated.  A follow up colonoscopy is recommended  3-5 years later.


Villous adenomas have a shaggy surface with papillary fronds and tend to be flatter lesions.

They have a greater propensity to become malignant.  Invasive cancer is seen in about .5% of adenomas less than 1cms, 5% in the adenomas that range in size from 1-1.9cms, and in 10% that are greater than 2cms.   One third of patients with have benign disease benign, one third have carcinoma in situ, and one third will demonstrate invasive carcinoma.



Villous Adenoma
The broad based polyp with fissures looks more like a tubular adenoma but it turned out to be a villous adenoma.  The histopathology is not from the same patient but shows the histopathological equivalent of the characteristic papillary fronds.  The barium enema on the other hand is from the same patient.

12113 colon large bowel sigmoid colon fx mass fx polyp polypoid mass dx villous adenoma grosspathology Courtesy Ashley Davidoff MD see imaging 12112

12156 colon large bowel fx polyp mass dx villous adenoma benign tumor histopathology mount Courtesy Barbara Banner MD 5star



Villous Adenoma of the Sigmoid Colon
The single contrast barium enema shows a sessile mass that is in the 2-3cms range.  The gross pathological specimen is noted above and at pathology was shown to be a villous adenoma.

12112c01 colon large bowel sigmoid colon fx mass fx polyp polypoid mass dx villous adenoma BE barium enema Courtesy Ashley Davidoff MD see pathology 12113