Intramural Benign Gastric Tumors



Intramural Benign Gastric Tumors


Michael P. Federle, MD, FACR





Key Facts


Terminology



  • Benign mass composed of 1 or more tissue elements of gastric wall


  • 50% of all benign tumors are intramural



    • Remainder are polyps


    • GIST > lipoma, leiomyoblastoma, lymphangioma, neural tumors


Imaging



  • UGI series: Intact mucosa, obtuse or right angles with wall


  • GIST: Often large with central necrosis and ulceration of overlying mucosa on CT



    • Central area of low attenuation (hemorrhage, necrosis, or cystic formation)


    • Most GIST > 2 cm have necrosis ± cavitation


  • Lipoma: Most common in antrum



    • May prolapse through pylorus into duodenum


    • Well-circumscribed areas of uniform fatty density = definitive diagnosis


Top Differential Diagnoses



  • Gastric carcinoma


  • Gastric metastases and lymphoma


  • Ectopic pancreatic tissue


  • Pancreatic pseudocyst


  • Splenosis


  • Gastric ulcer


  • Hematoma/seroma


Diagnostic Checklist



  • Isolated gastric target lesion = GIST


  • Multiple target lesions = metastases






(Left) Graphic shows a “generic” intramural gastric mass with intact mucosa and slightly obtuse or right angles at the interface with the gastric wall. (Right) Axial CECT shows a discrete fat-density mass image within the gastric wall with intact, stretched mucosa, diagnostic of a lipoma.






(Left) Upper GI series shows a gastric antral mass image with a central ulceration image, typical of a gastric GIST. Note the otherwise intact mucosa over the mass, even with preservation of the areae gastricae. (Right) Endoscopic photograph in the same patient shows the submucosal benign gastric GIST image with central ulceration image.



TERMINOLOGY


Definitions



  • Benign mass composed of 1 or more tissue elements of gastric wall


IMAGING


General Features



  • Best diagnostic clue



    • Intramural mass with smooth surface and slightly obtuse borders


  • Other general features



    • Types of intramural benign gastric tumors



      • Gastrointestinal stromal tumor (GIST)


      • Lipoma, leiomyoblastoma, lymphangioma, neural tumors


Radiographic Findings



  • Upper GI series



    • Discrete mass, solitary (usually) or multiple


    • Smooth surface lesion etched in white (double contrast, profile view)


    • Borders form right angle or slightly obtuse angles with adjacent gastric wall (profile view)


    • Intraluminal surface of tumor has abrupt, well-defined borders (en face view)


    • Usually intact overlying mucosa; normal areae gastricae pattern


    • “Bull’s-eye” or “target” lesions: Central barium-filled crater within mass (ulceration)



      • ± giant, cavitated lesions (GIST)


    • Pedunculated; may prolapse into duodenum


    • GIST



      • Most common; may occur anywhere in GI tract


      • Several mm to 30 cm


      • Only 1-2% of GIST are multiple


      • ± extragastric extensions (86%): Gastrohepatic ligament, gastrosplenic ligament, lesser sac


    • Lipoma, lymphangioma: Tendency to change in size and shape by peristalsis or palpation


    • Schwannoma and neurofibroma: Multiple lesions with associated abnormalities


CT Findings

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Jun 8, 2016 | Posted by in GENERAL RADIOLOGY | Comments Off on Intramural Benign Gastric Tumors

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