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Learning Modules ❯ Gastrointestinal

Duodenal Adenocarcinoma Extends to Ampulla

Duodenal Adenocarcinoma

Duodenal Adenocarcinoma Simulates a Pancreatic Mass

“ Carcinoid tumors of the gastrointestinal tract are a biologically heterogeneous group of tumors with a spectrum ranging from benign indolent tumors to aggressive metastatic malignancies. Imaging can play an important role in multidisciplinary identification and management of this disease.”
Imaging Features of Carcinoid Tumors of the Gastrointestinal Tract
Ganeshan D et al.
AJR 2013; 201:773-786

Carcinoid Tumor of the Small Bowel: Facts

Most common in ileum and least common in duodenum
Average incidence in US is around 1 in 100,000 cases
More common in men
More common in African-Americans and lower for Hispanics
Epidemiology of cancer of the small intestinePan SI, Morrison HWorld J Gastrointest Oncol 2011 March 15; 3(3):33-42

Carcinoid Tumors: Clinical Presentation

Incidental finding on CT or endoscopy
Carcinoid syndrome
Bowel obstruction
Perforation
Intussusception
Bowel ischemia
GI Bleeding
Fact: symptoms will vary depending on site of primary (i.e. vomiting common in gastric carcinoid and rectal pain and bleeding in colonic carcinoids)

Duodenal Carcinoid Tumors (NETs): Fact

Unique from other small bowel carcinoid tumors
Serotonin excess and carcinoid syndrome rarely seen as they rarely rise from enterochromaffin cells. They arise from gastrin producing G cells (result in duodenal gastrinomas) or somatostatin producing D cells (duodenal somatostatinomas)
D-cell duodenal somatostatinomas arise in periampullary region and are associated with neurofibromatosis type I

Duodenal Carcinoid Tumors (NETs): Facts

On CT these lesions are small but enhance intensely on arterial and venous phase images
When periampullary they may obstruct the common bile duct and present with jaundice.

Ileal and Jejunal Carcinoid Tumors (NETs)

Account for 26% of GI Mets
Ileum is most common site of small bowel carcinoid
Arterial phase imaging with MPR imaging is critical for CT detection of these lesions. Masses are usually in the 2 cm or greater size range
Desmoplastic reaction in mesentery as well as mesenteric masses is common
Up to 40% of these tumors are multifocal

Carcinoid Tumor: CT Findings

Primary mass in bowel or in the mesentery
Desmoplastic reaction in the mesentery
Calcification of mesenteric mass
Liver metastasis (hypervascular)

“ CT enteroclysis findings were positive in 19 patients and negative in 25 patients. The sizes of the carcinoid tumors identified were 5-30 mm in axial diameter. These tumors were depicted as focal nodular lesions located in the small-bowel wall or as intraluminal polypoid masses with marked enhancement.”
Value of CT Enteroclysis in Suspected Small-Bowel Carcinoid Tumors
Kamaoui I et al.
AJR 2010;194:629-633

“The overall sensitivity and specificity of CT enteroclysis in identifying patients with small-bowel carcinoid tumors were 100% and 96.2%, respectively. The negative predictive value of CT enteroclysis was 100% and the positive predictive value, 94.7%. Pathologic findings confirmed small-bowel carcinoid tumors in 18 patients.”
Value of CT Enteroclysis in Suspected Small-Bowel Carcinoid Tumors
Kamaoui I et al.
AJR 2010;194:629-633

Duodenal NET c/w Carcinoid

Duodenal Carcinoid Tumor

Pancreas PET vs Duodenal Carcinoid

Carcinoid Tumor in Duodenum (1 cm)

Carcinoid Tumor Duodenum

PNET of the Duodenum