Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Clinical features | Diagnosis | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Gonzalez RS. Adenoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ampullaadenoma.html. Accessed March 19th, 2024.
Definition / general
- Dysplastic, premalignant lesion of ampulla of Vater
Essential features
- Essentially the ampullary counterpart to colonic tubular / tubulovillous adenoma
ICD coding
- ICD-10: D37.6 - Neoplasm of uncertain behavior of ampulla of Vater
Epidemiology
- < 10% of periampullary neoplasms
- Age range 32 - 86 years (Am J Clin Pathol 2009;132:506)
- Incidence 1:1,000 - 2,000 based on autopsy studies
- Generally occurs in older patients
- Increased incidence in familial adenomatous polyposis syndrome
Clinical features
- Usually asymptomatic but can cause gastric outlet obstruction or bleeding and rarely acute pancreatitis, biliary obstruction or intussusception
- Excellent prognosis if completely excisedโจ
- Often associated with concurrent pancreatic intraepithelial neoplasia (Mod Pathol 2001;14:139)
Diagnosis
- Endoscopic impression, confirmed on biopsy
Case reports
- 49 year old woman with intussusception (Case Rep Gastroenterol 2016;10:545)
- 53 year old man with common bile duct stricture (Cytojournal 2017;14:19)
- 74 year old man with concurrent ampullary small cell neuroendocrine carcinoma (World J Gastroenterol 2008;14:4709)
- 78 year old man with ampullary adenoma (J Med Case Rep 2014;8:228)
- 81 year old man with progression to carcinoma (Am J Case Rep 2015;16:586)
Treatment
- Early or relatively confined lesions may be excised by endoscopic polypectomy or ampullectomy (Am J Clin Pathol 2009;132:506)
- Otherwise, requires pancreatoduodenectomy
Gross description
- Polypoid / exophytic mass
Microscopic (histologic) description
- Tubular, villous or mixed, similar to adenomas in colon, with approximately half tubular and half villous (Am J Clin Pathol 2009;132:506)
- Dysplastic epithelium may have only subtle changes of mild cellular stratification and fine chromatin pattern
- Often contain prominent Paneth cells (with coarse, large, red-pink, refractile granules in supranuclear cytoplasm), endocrine cells (dark, red-purple, fine small granules in basal cytoplasm) and goblet cells
- May show high grade dysplasia or give rise to adenocarcinoma
Microscopic (histologic) images
Cytology description
- Endoscopic brush cytology is sensitive and specific for adenoma / carcinoma, although diagnosis of adenoma does not exclude coexisting carcinoma (Am J Clin Pathol 1998;109:540)
Molecular / cytogenetics description
- Sporadic and familial adenomatous polyposis related adenomas show similar molecular features to colorectal adenoma, with presence of APC and KRAS mutations
- BRAF mutations, p53 alterations and DNA mismatch repair abnormalities are rare (Am J Surg Pathol 2008;32:1388)
Sample pathology report
- Ampulla, polypectomy:
- Ampullary adenoma (low grade dysplasia)
Differential diagnosis
- Duodenal (nonampullary) adenoma:
- Anatomic site is only distinction
- Intra-ampullary papillary tubular neoplasm:
- Occurs deeper within the ampulla
- May have pancreatobiliary type or intestinal type epithelium (Am J Surg Pathol 2010;34:1731)
Board review style question #1
Which of the following is true about adenomas of the ampulla of Vater?
- BRAF mutations are rarely seen
- Cases must be managed with pancreatoduodenectomy
- Patients with Lynch syndrome are at significantly increased risk
- Progression to adenocarcinoma is unusual
Board review style answer #1
A. BRAF mutations are rarely seen. KRAS and APC mutations are more common, both in sporadic cases and in those from patients with familial adenomatous polyposis.
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Board review style question #2
Board review style answer #2
B. KRAS mutations are most commonly seen in ampullary adenomas, along with APC mutations.
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