Colon
Mesenchymal tumors
Pyogenic granuloma
Author: Raul S. Gonzalez, M.D.
Topic Completed: 1 June 2017
Minor changes: 1 October 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed search: colonic pyogenic granuloma
Table of Contents
Definition / general | Essential features | Terminology | Sites | Clinical features | Case reports | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Differential diagnosis | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez R. Pyogenic granuloma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumorpyogenicgranuloma.html. Accessed January 24th, 2021.
Definition / general
- Benign capillary hemangioma forming a colonic polyp
Essential features
- Very rare
- Can cause rectal bleeding
Terminology
- Also called lobular capillary hemangioma
Sites
- Usually occurs in skin or oral cavity; gastrointestinal tract cases are very rare
Clinical features
- Presents clinically as rectal bleeding and anemia
Case reports
- 18 month old girl and 5 year old girl with rectal bleeding (J Pediatr Gastroenterol Nutr 2006;43:119)
- 62 year old woman with rectal bleeding (Ann Diagn Pathol 2005;9:106)
Clinical images
Images hosted on other servers:
Jejunal pyogenic granuloma
Upper duodenum findings
Endoscopic duodenal mucosal resection
Gross description
- Pedunculated or sessile polyp
- May appear black and necrotic
Microscopic (histologic) description
- Lobular arrangement of capillaries within edematous, inflamed stroma
- Endothelial cells often swollen
- Often shows surface ulceration; sometimes shows mitotic figures
Microscopic (histologic) images
Images hosted on other servers:
High power H&E
IHC for CD31 and CD34
Duodenum-edematous granulation tissue
Jejunum postsurgical pyogenic granuloma
Jejunum-CD34
Positive stains
- Vascular markers, such as CD34 (Am J Surg Pathol 1995;19:1054)
Differential diagnosis
- Bacillary angiomatosis: Warthin-Starry stain positive
- Granulation tissue: lacks a lobular arrangement
- Inflammatory polyp: lacks a lobular arrangement
- Kaposi sarcoma: positive for HHV8
Board review style question #1
A 21-year old man presents to his physician, complaining of hematochezia. Colonoscopy shows a small, pedunculated polyp. Microscopically, the polyp is mostly composed of inflammation and small blood vessels. Which of the following findings would favor a diagnosis of pyogenic granuloma?
A. Dilated, ectatic crypts
B. Lobular architecture
C. Positivity for HHV8
D. Surface adenomatous change
E. Viral cytopathic effect
A. Dilated, ectatic crypts
B. Lobular architecture
C. Positivity for HHV8
D. Surface adenomatous change
E. Viral cytopathic effect
Board review style answer #1
