PMC3278634_01
Computed tomography and fluorodeoxyglucose-positron emission tomography (FDG-PET) computed tomography (CT) scans. Images showed a huge heterogeneous mass that is originated from stomach (A) and the tumor seemed to invade pancreas and spleen (B). A FDG-PET CT scan showed FDG uptake in the lesion (C).
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F1
Contrast-enhanced abdominal computed tomography (CT) and F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) CT showed an approximately 12 cm sized heterogeneous mass located from fundus to mid body of stomach, which seemed to invade pancreas, spleen and left adrenal gland (Fig. 1A-C).
Endoscopic finding of a huge subepithelial lesion with central ulceration was noticed on fundus.
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F2
Endoscopic biopsy performed in our institution and pathologic report revealed a spindle cell tumor consistent with GIST (Figs. 2, 3).
Histological study showing spindle cell tumor (H&E, x100).
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F3
Endoscopic biopsy performed in our institution and pathologic report revealed a spindle cell tumor consistent with GIST (Figs. 2, 3).
Immunohistochemistry finding revealing positive staining for CD34 (x10).
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F4
Results of immunohistochemical stain: the tumor cell was positive for CD34 and c-kit (CD117), weak positive for smooth muscle actin; whereas S-100 was negative (Fig. 4).
Neoadjuvant therapy with imatinib for 4 months: there was no evidence of mass lesion in stomach on computed tomography.
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F5
And 4 months after follow-up CT, there was no evidence of mass lesion in the stomach (Fig. 5); on the gastroduodenoscopy, the mass lesion was invisible with only an ulcerative lesion observed in the same location (Fig. 6).
Fluorodeoxyglucose-positron emission tomography showed a hypermetabolic lesion around medial side of spleen.
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F7
Although the mass lesion was not revealed clearly at the follow-up imaging study (Fig. 7), we planned operation to achieve curative resection of the tumor. 5 months after the treatment with imatinib, the patient underwent total gastrectomy and splenectomy.
Histological study showing a residual tumor in fibrotic tissue (H&E, x20).
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F8
Around the residual tumor, hyalinized fibrosis, inflamed granulation tissue, dystrophic calcification, and necrosis and abscess were seen (Fig. 8).