Unsuspected gastric glomus tumour

Abstract

Gastric glomus tumours (GGTs) are rare predominantly benign, mesenchymal neoplasms that commonly arise from the muscularis or submucosa of the gastric antrum and account for <1% of gastrointestinal soft-tissue tumours. Historically, GGT has been difficult to diagnose preoperatively due to the lack of unique clinical, endoscopic and CT features. We present a case of an incidentally identified GGT in an asymptomatic man that was initially considered a neuroendocrine tumour (NET) by preoperative fine-needle aspiration biopsy with focal synaptophysin reactivity. An elective robotic distal gastrectomy and regional lymphadenectomy were performed. Postoperative review by pathology confirmed the diagnosis of GGT. GGTs should be considered by morphology as a differential diagnosis of gastric NET on cytology biopsy, especially if there is focal synaptophysin reactivity. Additional staining for SMA and BRAF, if atypical/malignant, can help with this distinction. Providers should be aware of the biological behaviour and treatment of GGTs.

Keywords: Gastric cancer; Pathology; Stomach and duodenum; Surgical oncology.

Figure 1

CT of GGT case. GGT, gastric glomus tumour.

Figure 2

Endoscope of GGT case. GGT, gastric glomus tumour.

Figure 3

FNA biopsy with cytology of dark round blue cells, round cells with dispersed chromatin on histology and synaptophysin weak, dot-like Golgi-appearing reactivity, unusual for GT. FNA, fine-needle aspirate; GT, glomus tumour.

Figure 4

Histopathology and SMA immunostain of gastric glomus tumour resection. H&E low power with submucosal (gastric mucosa to far left of picture) gastric glomus tumour (left) with prominent pericytoid vasculature (glomangioma), higher magnification of round to ovoid cells with cytoplasmic clearing, ‘fried-egg’ appearance (middle), SMA immunostain positivity (right).