Gastrointestinal Occurrence of a Glomus Tumor

Abstract

Glomus tumors are benign subepithelial mesenchymal neoplasms generally found in the fingers. It is rare to find a glomus tumor in the gastrointestinal tract. This is a case of a gastric glomus tumor (GGT). It is important to understand the difference betwen a glomus tumor and a gastrointestinal stromal tumor (GIST), which is far more common. The patient is a 26 year old Caucasian female who, for the past one year, had been visiting the gastroenterology clinic with complaints of epigastric abdominal pain, constipation, diarrhea, and heartburn. She was a moderately built individual with no abnormal vitals or notable findings on physical examination. We decided to do an EGD, and a mass in the body of the stomach was discovered. CT abdomen revealed a high density nodular lesion. EUS showed a 2.5cm x 2.2cm submucosal mass with mixed echogenicity and cystic spaces, arising from the muscularis propria of the stomach wall. The biopsy was consistent with a neuroendocrine lesion. Neuroendocrine markers were negative. However, smooth muscle actin and vimentin were strongly immunoreactive. Serotonin levels were normal, and octreotide scan revealed a faint glow in the tumor. Surgery was consulted and laparoscopic partial gastrectomy was performed. Pathology of the wedge resection revealed a gastric glomus tumor 1.8cm in diameter with well-defined margins and no evidence of malignancy. Subepithelial tumors of the gastrointestinal tract include carcinoid tumors, lymphomas, glomus tumors, and GIST. GIST, being the most common, are thought to arise from the interstitial cells of Cajal of the autonomic nervous system of the intestine. Glomus tumors arise from the glomus body in the intramuscular layer, typically in the antrum of the stomach. Both appear on CT as well-circumscribed homogenous masses, and on EUS as hypoechoic masses. However, GGT can be distinguished from GIST based on immunohistochemisty. GIST is typically positive for c-kit (CD117), whereas GGT may test positive for smooth muscle actin, laminin, collagen type IV, desmin, and vimentin.2680_A Figure 1. MR Abdomen, showing a 2.2cm homogenously-enhancing subepithelial gastric antral wall mass.2680_B Figure 2. Microscopic examination, showing multiple blood vessels surrounded by round glomus cells.Even though EUS-FNA differentiates GTs from more aggressive gastric tumors with a 95.6% accuracy, surgery is still preferred. According to the National Comprehensive Cancer Network, if the GIST is >2cm it should be surgically resected. Even if there were any doubt between a GT or GIST, wedge resection is the therapeutic management of choice. This rare case taught us how to diagnose and treat a gastrointestinal glomus tumor.