2018 Volume 57 Issue 6 Pages 307-311
Background : Glomus tumor represents a neoplastic proliferation of modified smooth muscle cells of the glomus body. The tumor usually occurs in the deep dermis or subcutaneous tissue of the extremities, and only rarely occurs in the stomach. Herein, we report a case of glomus tumor of the stomach that was diagnosed preoperatively by endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA).
Case : A 44-year-old woman was referred to us for investigation of a gastric submucosal tumor. The specimen obtained by EUS-FNA showed variable cohesive cell clusters composed of uniform round cells admixed with myxoid material and capillary vessels. The nuclei were round to oval, with smooth nuclear membranes and evenly distributed salt-and-pepper chromatin. The most critical differential diagnosis was neuroendocrine tumor, because of the cytomorphological resemblance. However, the cytomorphological finding of cohesive clusters intermingled with myxoid material, which is usually not seen in neuroendocrine tumors, was helpful to diagnose this case as a glomus tumor. Immunohistochemical studies revealed positive staining for αSMA and synaptophysin, and negative staining for CD56, chromogranin A and c-kit, findings compatible with the diagnosis of glomus tumor.
Conclusions : Careful morphological examination and immunohistochemistry are needed to diagnose glomus tumor in EUS-FNA specimens.
