PMC5928285_01
Upper gastrointestinal endoscopy showed a 30 mm submucosal polypoid lesion on the posterior wall of the proximal stomach (a). Endoscopic-ultrasound showed that the submucosal tumor was homogenous with an echogenicity similar to that of the normal muscularis (arrow) (b).
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An asymptomatic 60-year-old Japanese woman with no significant past medical history underwent routine upper endoscopy, which revealed a 30 mm submucosal lesion on the posterior wall of the proximal stomach (Fig. 1a). Endoscopic ultrasound showed a homogeneous low echo lesion in the muscularis of the gastric wall (Fig. 1b).
Contrast-enhanced computed tomography (CT) scan revealed poorly enhanced tumors in the stomach (a) and the anterior abdominal wall (b) (arrows). Axial enhanced T1-weighted image on magnetic resonance imaging showed similarly homogeneous moderate enhancement in both gastric (c) and abdominal wall lesions (d) (arrows). 18F-fluorodeoxyglucose positron emission tomography CT scan revealed 18FDG uptake only in the abdominal wall lesion with a maximum standardized uptake value of 1.92 (e, f) (arrows).
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CT scan revealed poorly enhancing lesions in the stomach (Fig. 2a) and anterior abdominal wall (Fig. 2b). Axial T2 - weighted images on MRI scan showed a homogeneous low signal intensity and enhanced T1-weighted image showed homogeneous moderate enhancement of both the gastric (Fig. 2c) and abdominal wall lesions (Fig. 2d). Fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG-PET) CT revealed 18F-FDG uptake only in the abdominal wall tumor with a maximum standardized uptake value (SUVmax) of 1.92 (Fig. 2e, f).
(a) The gastric lesion was resected with laparoscopic-endoscopic cooperative surgery and showed two solid tumors, 23 and 22 mm in diameter. (b) Histopathological findings established the diagnosis of gastric leiomyomata, with spindle-shaped cells arranged in an interlacing and palisading pattern with few mitoses (Hematoxylin-Eosin stain, 40x). (c) Immunostaining revealed that the cells were positive for alpha-smooth muscle actin (100x). (d) Core needle biopsy of the abdominal wall tumor revealed polygonal cells with eosinophilic, granular cytoplasm and vesicular nuclei spreading in the muscle and adipose tissue (Hematoxylin-Eosin stain, 100x). (f) The cells stained positive for S-100 (100x).
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The gastric submucosal tumor was composed of two white solid areas, each about 20 mm (Fig. 3a). Histopathologic examination showed elongated fusiform cells with abundant eosinophilic cytoplasm proliferating in a palisading manner (Fig. 3b) with few mitoses. Immunohistochemically, alpha-smooth muscle actin was positive in the gastric lesion (Fig. 3c) but C-kit and CD34 were negative. Histopathologically, the ultrasound-guided core needle biopsy of the abdominal wall lesion revealed sheets of polygonal cells with eosinophilic, granular cytoplasm and vesicular nuclei (Fig. 3d), and S-100 was positive (Fig. 3f).