Gastric glomus tumor diagnosed by fine needle aspiration of the stomach: A report of two cases and review of the literature.

Glomus tumors make up 1% of stromal tumors of the stomach. Radiologic diagnosis of glomus tumors can be challenging as they share imaging characteristics with other neuroendocrine tumors and gastrointestinal stromal tumors. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been reported as a useful method for the evaluation of gastrointestinal lesions. We report two cases of gastric glomus tumors in which EUS-FNA diagnosis was challenging. Cytologically, neoplastic cells were round to oval, uniform, bland appearing epithelioid cells with delicate chromatin and inconspicuous to vague nucleoli. Both samples lacked worrisome features such as high nuclear grade, high mitotic rate, and necrosis. Neoplastic cells were negative for Cam5.2 and AE1/AE3 with focal expression of synaptophysin in one of the cases. A definitive diagnosis was not made based on FNA. Familiarity with glomus tumors in the GI system and procurement of adequate material for cell block allowing the use of immunohistochemistry may allow an accurate preoperative diagnosis.