Computed tomographic characteristics of gastric schwannoma

Abstract

Objective: This study aimed to characterize the computed tomographic (CT) features of gastric schwannoma (GS).

Methods: We retrospectively reviewed CT images of 19 cases of histologically proven GS between January 2010 and December 2015. Tumor location, size, contour, margin, growth pattern, and degree and pattern of enhancement, perigastric lymph nodes, ulceration, necrosis, and calcification were evaluated.

Results: GS was located in the gastric body (73.7%), gastric antrum (15.8%), and gastric fundus (10.5%), with a mean maximum diameter of 4.5 ± 1.8 cm. All tumors presented as oval, well-defined solid masses, with exophytic (36.8%), endoluminal (15.8%), or mixed (47.4%) growth patterns. Ulcers (57.9%) and perigastric lymph nodes (47.4%) were observed. Moderate enhancement (87.5%) was observed in the portal phase. Eighteen (94.7%) cases showed homogeneous enhancement.

Conclusions: GS typically presents as a mass in the stomach with an exophytic or mixed growth pattern, moderate homogeneous enhancement, and is prone to be accompanied by perigastric lymph node inflammatory reactive swelling. Larger GSs are more likely to be associated with ulcers.

Keywords: Gastric schwannoma; clinicopathology; computed tomography; exophytic growth; lymph node; stomach; ulcer.

Figure 1.

Portal phase-enhanced CT scans of three patients with gastric schwannomas. (a) Axial CT image shows an endoluminal tumor growth with an ulceration (arrow) in the lesser curvature of the gastric body in a 50-year-old man who presented with chest pain (Patient 3, Table 1) (b) Axial CT image shows an exophytic tumor growth in the posterior wall of the fundus in a 63-year-old woman with epigastric pain (Patient 5, Table 1). (c, d) Transverse and sagittal CT images show a mixed growth gastric schwannoma with an ulceration (arrow) in the greater curvature of the gastric body in a 52-year-old woman who presented with epigastric pain (Patient 19, Table 1). CT: computed tomography.

Figure 2.

(a, b) A gastric schwannoma in a 56-year-old woman who presented with epigastric pain (Patient 2, Table 1). (a) A plain CT scan shows a tumor arising from the posterior wall of the gastric fundus. (b) Portal phase of the CT scan shows that the tumor is moderately, homogeneously enhanced. (c, d) A gastric schwannoma in a 51-year-old woman without any symptoms (Patient 17, Table 1). (c) A plain CT scan shows a tumor arising from the greater curvature of the gastric body, with curvilinear calcification seen at the margin of the mass (white arrow). (d) Portal phase CT scan shows that the tumor is markedly, homogeneously enhanced. CT: computed tomography.

Figure 3.

Axial portal phase computed tomographic image shows perigastric lymph nodes (arrow) in a 58-year-old woman with gastric schwannoma (arrow head) (Patient 1, Table 1).

Figure 4.

Histopathological and immunophenotypic features of Patient 17 (Table 1). The tumor shows (a) a biphasic pattern with cellular Antoni A and hypocellular Antoni B areas (hematoxylin and eosin stain; original magnification, ×200) and (b) S-100 positive staining in elongated tumor cells and negative staining in Antoni B areas.

Figure 5.

Histopathological and immunophenotypic features of Patient 19 (Table 1). The tumor is (a) mainly composed of spindle-shaped cells with a characteristic peripheral lymphoid cuff (hematoxylin and eosin stain; original magnification, ×100). (b) The tumor is positive (<10%) for Ki-67.

Figure 6.

Graph shows computed tomographic values of 16 patients in each phase of a dynamic contrast-enhanced computed tomographic scan. PS: plain scan, AP: arterial phase, PP: portal phase.