Colon
Carcinoma
Low grade tubuloglandular adenocarcinoma
Author: Raul S. Gonzalez, M.D.
Last author update: 29 January 2021
Last staff update: 22 December 2021
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Tubuloglandular adenocarcinoma [title]
Table of Contents
Definition / general | Essential features | Epidemiology | Clinical features | Prognostic factors | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Sample pathology report | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez RS. Low grade tubuloglandular adenocarcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumorlowgradetubulo.html. Accessed December 26th, 2024.
Definition / general
- Uncommon type of colorectal adenocarcinoma seen in patients with inflammatory bowel disease (Am J Surg Pathol 2006;30:1022)
Essential features
- Arises in patients with ulcerative colitis or Crohn's disease
- Low grade histology may be difficult to distinguish from benign glands
- Can arise directly from low grade dysplasia
Epidemiology
- ~10% of inflammatory bowel disease associated colon carcinomas are low grade tubuloglandular subtype
Clinical features
- Median age 41.5 years
- More common in ulcerative colitis than Crohn's disease
- Patients may have synchronous conventional colorectal adenocarcinoma (see IBD associated carcinoma)
Prognostic factors
- Patients generally do well unless a synchronous conventional colorectal carcinoma is also present
Gross description
- May not be identifiable grossly; may be only identified on random sections
Microscopic (histologic) description
- Small or medium sized glands with round or tubular shape
- Malignant glands are extremely well differentiated and might only be identifiable as malignant based on location deep within the bowel wall
- Desmoplasia is rare or absent
- Overlying mucosa may show only low grade dysplasia
- Areas of conventional adenocarcinoma may be visible
Microscopic (histologic) images
Contributed by Raul S. Gonzalez, M.D.
Low grade tubuloglandular adenocarcinoma in ulcerative colitis patient
Background colitis
Negative stains
- MUC6 (0%)
Molecular / cytogenetics description
- Often harbors IDH1 mutation (Am J Surg Pathol 2014;38:1147)
- 55% of cases lack MLH1 expression by immunohistochemistry
Sample pathology report
- Ascending colon, resection:
- Low grade tubuloglandular adenocarcinoma (see synoptic report)
- Background severely active chronic colitis, consistent with patient’s reported history of ulcerative colitis.
Board review style question #1
Low grade tubuloglandular adenocarcinoma of the colon arises in patients with what risk factor?
- Familial adenomatous polyposis
- Inflammatory bowel disease
- Lynch syndrome
- Prior personal history of colon cancer
Board review style answer #1
