Synchronous gastric leiomyoma and intramuscular abdominal wall granular cell tumor with similar imaging features: A case report

Abstract

Introduction: Gastric leiomyomas are benign mesenchymal tumors, comprising about 2.5% of gastric neoplasms, which can be difficult to differentiate from gastrointestinal stromal tumors which have malignant potential. Granular cell tumors in the abdominal wall are also rare. Since mesenchymal tumors are difficult to diagnose by imaging, further studies are needed to establish the diagnosis.

Presentation of case: A 60-year-old asymptomatic woman underwent routine upper endoscopy and was found to have a gastric submucosal lesion. Computed tomography scan also showed an abdominal wall mass. The appearance of both lesions on imaging studies were similar, but it was unclear if the two lesions had the same origin. Endoscopic ultrasound-guided fine needle aspiration biopsy of the gastric lesion was insufficient to establish the diagnosis. Laparoscopic-endoscopic cooperative resection of the gastric lesion and ultrasound-guided core-needle biopsy of the abdominal wall mass enabled pathological diagnosis of both lesions.

Discussion: Diagnostic imaging findings of these two lesions were similar. Histologic and immunohistochemical studies are essential to establish a definitive diagnosis. Laparoscopic-endoscopic cooperative surgery may be an effective minimally invasive approach, allowing both pathological diagnosis and complete resection of a gastric submucosal tumor, especially when endoscopic-ultrasound guided fine needle aspiration or biopsy fails to make the diagnosis.

Conclusion: Laparoscopic-endoscopic cooperative surgery can be an effective minimally invasive approach to resect some lesions. This is first report of the patient with a synchronous gastric leiomyoma and an intramuscular granular cell tumor in the abdominal wall.

Keywords: Case report; Gastric leiomyoma; Granular cell tumor; Laparoscopic-endoscopic cooperative surgery.

Fig. 1

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).

Fig. 2

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).

Fig. 3

(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, 40×). (c) Immunostaining revealed that the cells were positive for α-smooth muscle actin (100×). (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, 100×). (f) The cells stained positive for S-100 (100×).