Small Intestinal GIST in a Young Adult Woman
Small Intestinal GIST in a Young Adult Woman
A 30-year-old Caucasian ethnic Albanian woman from Kosovo presented with abdominal pain, nausea and vomiting. Subsequently, a tumor was detected in her small intestine (duodenojejunum), as an infiltrating mass approximately 10cm in diameter that had infiltrated her pancreatic capsule and radix mesentery. The tumor was resected en bloc and a duodenojejunal terminal-terminal anastomosis was performed. On histological examination, differential diagnoses considered were leiomyosarcoma versus GIST. Immunohistochemistry confirmed the diagnosis of malignant GIST.
The tumor was large, bulky, 10cm in diameter, with tan-brown appearance, as well as with massive hemorrhagic necrosis and cyst formation.
On histological examination, the tumor showed transmural growth, deep infiltrative pattern and malignant feature; it was high risk according to Fletcher's criteria with mitotic count >5 per 50 high-power field (HPF), dense cellularity with plump spindle cells with eosinophilic cytoplasm within variably hyalinized edematous stroma, skeinoid fibers (extracellular collagen globules) and foci of hemorrhage and necrosis. In addition, the tumor was composed of areas with epithelioid morphology (Figures 1, 2 and 3). The immunohistochemistry results showed high expression of proto-oncogene c-Kit (CD117), CD34 and vimentin, whereas α-smooth muscle actin was focally positive. Desmin and S-100 protein were negative. Ki-67 expression showed low proliferative index (10%), (Figures 4, 5, 6, 7 and 8).
(Enlarge Image)
Figure 1.
Intestinal submucosal gastrointestinal stromal tumor with dense cellularity, short fascicles and whorls. Hematoxylin and eosin stain, 4×.
(Enlarge Image)
Figure 2.
Epithelioid differentiation with perinuclear and cytoplasmic vacuolization. Hematoxylin and eosin stain, 20×.
(Enlarge Image)
Figure 3.
Spindle cell area of gastrointestinal stromal tumor with nuclear pleomorphism. Hematoxylin and eosin stain, 40×.
(Enlarge Image)
Figure 4.
CD117(proto-oncogene c-Kit) strong and diffuse cytoplasmic staining, 20×.
(Enlarge Image)
Figure 5.
Vimentin, strong immunoreactivity, 20×.
(Enlarge Image)
Figure 6.
CD34strong and diffuse membrane staining, 20×.
(Enlarge Image)
Figure 7.
Smooth muscle actinfocal immunoreactivity of some smooth muscle differentiated cells, 10×.
(Enlarge Image)
Figure 8.
Ki-67 low proliferation index (10%), 40×.
Our final diagnosis was intestine GIST, with mixed spindle and epithelioid morphology.
Case Presentation
A 30-year-old Caucasian ethnic Albanian woman from Kosovo presented with abdominal pain, nausea and vomiting. Subsequently, a tumor was detected in her small intestine (duodenojejunum), as an infiltrating mass approximately 10cm in diameter that had infiltrated her pancreatic capsule and radix mesentery. The tumor was resected en bloc and a duodenojejunal terminal-terminal anastomosis was performed. On histological examination, differential diagnoses considered were leiomyosarcoma versus GIST. Immunohistochemistry confirmed the diagnosis of malignant GIST.
Macroscopic Features
The tumor was large, bulky, 10cm in diameter, with tan-brown appearance, as well as with massive hemorrhagic necrosis and cyst formation.
Histological and Phenotypic Findings
On histological examination, the tumor showed transmural growth, deep infiltrative pattern and malignant feature; it was high risk according to Fletcher's criteria with mitotic count >5 per 50 high-power field (HPF), dense cellularity with plump spindle cells with eosinophilic cytoplasm within variably hyalinized edematous stroma, skeinoid fibers (extracellular collagen globules) and foci of hemorrhage and necrosis. In addition, the tumor was composed of areas with epithelioid morphology (Figures 1, 2 and 3). The immunohistochemistry results showed high expression of proto-oncogene c-Kit (CD117), CD34 and vimentin, whereas α-smooth muscle actin was focally positive. Desmin and S-100 protein were negative. Ki-67 expression showed low proliferative index (10%), (Figures 4, 5, 6, 7 and 8).
(Enlarge Image)
Figure 1.
Intestinal submucosal gastrointestinal stromal tumor with dense cellularity, short fascicles and whorls. Hematoxylin and eosin stain, 4×.
(Enlarge Image)
Figure 2.
Epithelioid differentiation with perinuclear and cytoplasmic vacuolization. Hematoxylin and eosin stain, 20×.
(Enlarge Image)
Figure 3.
Spindle cell area of gastrointestinal stromal tumor with nuclear pleomorphism. Hematoxylin and eosin stain, 40×.
(Enlarge Image)
Figure 4.
CD117(proto-oncogene c-Kit) strong and diffuse cytoplasmic staining, 20×.
(Enlarge Image)
Figure 5.
Vimentin, strong immunoreactivity, 20×.
(Enlarge Image)
Figure 6.
CD34strong and diffuse membrane staining, 20×.
(Enlarge Image)
Figure 7.
Smooth muscle actinfocal immunoreactivity of some smooth muscle differentiated cells, 10×.
(Enlarge Image)
Figure 8.
Ki-67 low proliferation index (10%), 40×.
Our final diagnosis was intestine GIST, with mixed spindle and epithelioid morphology.
Source...