Colon
Polyps
Adenoma with invasive carcinoma
Author: Shilpa Jain, M.D.
Last author update: 1 September 2010
Last staff update: 26 May 2023 (update in progress)
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: Invasive carcinoma arising colonic adenoma
Table of Contents
Definition / general | Terminology | Epidemiology | Prognostic factors | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) imagesCite this page: Jain S. Adenoma with invasive carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumorcarcinomaarising.html. Accessed September 30th, 2023.
Definition / general
- Invasive only if cancer has invaded beyond muscularis mucosa into submucosa
- Can diagnose invasion without identification of submucosa if (a) marked desmoplasia, (b) infiltrative pattern, (c) ulceration or (d) clinical mass lesion
Terminology
- Recommended to NOT use "carcinoma in situ" terminology in colorectum; use either high grade dysplasia or invasive carcinoma
- Also called "malignant polyp"
Epidemiology
- Present in 5% of adenomas (G Chir 2001;22:26)
Prognostic factors
- Recurrent disease, nodal metastases or residual local disease: 20% incidence if cancer is near margin, is poorly differentiated or if angiolymphatic invasion is present
Case reports
- Adenoma with carcinoma and mixed carcinoid-adenocarcinoma (Pathol Int 2003;53:457)
- With sarcoid reaction in regional lymph nodes (J Clin Gastroenterol 1999;28:377)
- Squamous cell carcinoma arising in villous adenoma (Hum Pathol 1988;19:362)
- Metastatic signet ring cell carcinoma in adenoma (Arch Pathol Lab Med 2003;127:1509)
Treatment
- Polypectomy probably adequate unless margin involvement, poorly differentiated or angiolymphatic invasion (J Surg Oncol 1987;36:116, Dis Colon Rectum 2004;47:1789)
Microscopic (histologic) description
- How to Report:
- Report type of carcinoma, grade, presence of angiolymphatic invasion (tumor emboli in true endothelial lined channels away from tumor, not retraction artifact), status of resection margins (close to margin is within one high power field or 1-2 mm from diathermy or at diathermy), presence of dysplasia
- Sample report #1: poorly differentiated carcinoma arising within an adenoma, extending to resection margin, no angiolymphatic invasion
- Sample report #2: moderately differentiated carcinoma arising with an adenoma; tumor 2.5 cm from resection margin, no angiolymphatic invasion
Microscopic (histologic) images
Images hosted on other servers:
Arising in villous adenoma
