PMC9938401_01
Gross findings (a, b) and pathological findings of a resected intestinal specimen including H&E staining (c: x40) and positive immunohistochemistry findings of c-kit (d: x100) in case 1. Lower gastroendoscopic findings revealed a 5-cm elastic hard submucosal tumor at the anterior rectal wall (e). Gross findings (f) and pathological findings of a resected intestinal specimen, including H&E staining (g: x20) and positive immunohistochemistry findings of c-kit (h: x100) in case 2.
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F1
Lower gastroendoscopy revealed a 5-cm elastic hard submucosal tumor at the anterior rectal wall (Fig. 1e), and endoscopic ultrasonography revealed low-echoic contents with small cystic lesions. Pathological findings confirmed the diagnosis of GIST, and mitotic index was >5/50 HPF (Fig. 1f-h), classified as high risk according to the modified Fletcher classification.
18-fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT revealed increased FDG uptake at the lesions in the lower intraperitoneal cavity.
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F2
18-fluorodeoxyglucose positron emission tomography (PET)-CT showed increased 18-fluorodeoxyglucose uptake of the suspected tumor and other small lesions in the lower intraperitoneal cavity (Fig. 2a, b).
PMC9938401_02
Gross findings (a, b) and pathological findings of a resected intestinal specimen including H&E staining (c: x40) and positive immunohistochemistry findings of c-kit (d: x100) in case 1. Lower gastroendoscopic findings revealed a 5-cm elastic hard submucosal tumor at the anterior rectal wall (e). Gross findings (f) and pathological findings of a resected intestinal specimen, including H&E staining (g: x20) and positive immunohistochemistry findings of c-kit (h: x100) in case 2.
crg-2022-0017-0001-529002_f1.jpg
PMC9938401_02_crg-2022-0017-0001-529002_f1.jpg
F1
Lower gastroendoscopy revealed a 5-cm elastic hard submucosal tumor at the anterior rectal wall (Fig. 1e), and endoscopic ultrasonography revealed low-echoic contents with small cystic lesions. Pathological findings confirmed the diagnosis of GIST, and mitotic index was >5/50 HPF (Fig. 1f-h), classified as high risk according to the modified Fletcher classification.
Magnetic resonance image (MRI) revealed a newly detected metastatic hepatic tumor. c, d Follow-up MRI after 300 mg imatinib/day for 18 months following surgical treatment of rectal GIST led to metastatic hepatic tumor size reduction.
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F3
Four months after initiation of sunitinib, PET-CT, MRI, and contrast-enhanced CT revealed a newly detected metastatic hepatic tumor (Fig. 3a, b) with no change in the primary rectal tumor. Follow-up MRI showed no recurrence in the colon and reduced size of the metastatic hepatic tumor (from 17 mm x 15 mm x 14 mm to 12 mm x 10 mm x 8 mm) (Fig. 3c, d).