Presentation
Abdominal pain and mass feeling.
Patient Data
A well-defined, large heterogeneous, mostly cystic mass measuring about 116 x 97 x 71 mm in diameter is noted in the upper abdomen, between the left lobe of the liver and lesser curvature of the body of the stomach. The fat plane between the mass and gastric wall is obliterated. Hypo attenuated areas were noted in the tumoral mass in favor of cystic or necrotic changes. Enhancing solid components are present in the periphery of the lesion. Compression of the adjacent organs such as body of the pancreas is evident.
On post contrast arterial and portal venous phase CT scan a peripheral, dense, spotty enhancing mass lesion approximately 15 mm in diameter, was seen in the anterior inferior (5th) segment of the hepatic parenchyma. In the equilibrium phase the attenuated areas spread through the mass (filling in). The density of the lesion is almost the same as that of aorta in all phases of dynamic CT.
Also another mass lesion 14 mm in diameter was noted in the posterior inferior (6th) segment of the liver. At equilibrium phase, the mass shows delayed enhancement.
Case Discussion
Pathology proven gastric gastrointestinal stromal tumor (GIST).
Histopathology report:
Sections show well-defined tumoral tissue composed of spindle cells in fascicular & whorled pattern.
Hypercellular and hypocellular areas, edematous and myxoid stroma with hyalinization.
Thickened wall blood vessels, hemorrhage and cystic changes are also seen.
Nuclear atypia is mild. Mitosis is rare. Overlying gastric mucosa is intact.
No tumoral invasion into the mucosa is present.
The neoplastic cells express immunoreactivity as bellow:
C117: positive
CD34: positive
SMA: positive in few cells.
EMA: Negative.
Findings are consistent with gastrointestinal stromal tumor (GIST).
GISTs occur anywhere along the gastrointestinal tract. Common sites of involvement include stomach (70%) and small intestine (20-25%).