Diagnostic Challenge of Gastric Glomangioma Mimicking Gastrointestinal Stromal Tumor: A Case Report.

Abstract

Introduction: Gastric glomus tumors (GGTs) are rare benign mesenchymal neoplasms of the stomach, often mistaken preoperatively for more common submucosal lesions such as gastrointestinal stromal tumors (GISTs). Accurate diagnosis requires a combination of endoscopic ultrasonography, histopathology, and immunohistochemistry.

Case description: We report a 51-year-old female with a two-year history of epigastric burning, anorexia, and unexplained weight loss. Initial evaluation included EUS, which identified a 1.8 × 2.4 cm hypoechoic submucosal lesion arising from the muscularis propria at the gastric antrum. Contrast-enhanced CT demonstrated a 2 cm avidly enhancing antral lesion with persistent venous-phase enhancement; no evidence of lymphadenopathy or metastasis was noted. Subsequent EUS-guided fine-needle biopsy (FNB) demonstrated an epithelioid neoplasm. Initial immunohistochemistry excluded GIST (CD117-, DOG1-), leiomyoma (desmin-), and schwannoma (S100-). Additional glomus tumor-specific markers were not performed at this stage due to limited biopsy material and a stepwise diagnostic approach. Given the peri-pancreatic location, diagnostic uncertainty, and lesion size exceeding 2 cm, the decision was made to proceed with laparoscopic distal gastrectomy. Final histopathology confirmed glomangioma, positive for SMA and vimentin; Ki-67 ~1%; 0 mitoses per 50 high-power fields (HPF); no atypia, necrosis, lymphovascular invasion, or clear margins. Postoperative surveillance CTs showed no recurrence; no adjuvant therapy was indicated.

Conclusion: This case highlights the clinical and radiologic overlap between GGT and other submucosal gastric lesions. Comprehensive immunohistochemistry and careful surgical planning are essential for accurate diagnosis and management.