Features of gastric glomus tumor: a clinicopathologic, immunohistochemical and molecular retrospective study

• Published in: International journal of clinical and experimental pathology Vol. 7; no. 4; pp. 1438 - 1448
• Main Authors: Wang, Zhan-Bo, Yuan, Jing, Shi, Huai-Yin
• Format: Journal Article
• Language: English
• Published: United States e-Century Publishing Corporation 01.01.2014
• Subjects: Actins - metabolism; Adult; Aged; Base Sequence; Biomarkers, Tumor - metabolism; Collagen Type IV - metabolism; Female; Gastrointestinal Stromal Tumors - genetics; Gastrointestinal Stromal Tumors - metabolism; Gastrointestinal Stromal Tumors - pathology; Glomus Tumor - genetics; Glomus Tumor - metabolism; Glomus Tumor - pathology; Humans; Immunohistochemistry; Laminin - metabolism; Male; Middle Aged; Molecular Sequence Data; Mutation - genetics; Original; Proto-Oncogene Proteins c-kit - genetics; Proto-Oncogene Proteins c-kit - metabolism; Receptor, Platelet-Derived Growth Factor alpha - genetics; Receptor, Platelet-Derived Growth Factor alpha - metabolism; Retrospective Studies; Stomach - metabolism; Stomach - pathology; Stomach - ultrastructure; Stomach Neoplasms - genetics; Stomach Neoplasms - metabolism; Stomach Neoplasms - pathology; Vimentin - metabolism; diagnosis; immunohistochemistry; Glomus tumor; ultrastructure: stomach
• ISSN: 1936-2625

Glomus tumor (GT) of the stomach is a rare mesenchymal tumor. There have been few detailed studies on these tumors. A total of 1894 cases of resected gastric mesenchymal tumors were collected and eleven confirmed gastric GTs were studied. The clinical, pathological, immunohistochemical, ultrastructural and molecular characteristics of the tumors were analyzed through a retrospective study. Histologically, most tumors had gastric smooth muscle immediately adjacent and surrounding the tumor. Tumor cells around blood vessels were small, uniform, and round. Foci of hyaline and myxoid changes were observed. Prominent clear cell features were observed in two tumors. Positive expression of α-smooth muscle actin (α-SMA), laminin, collagen type IV, and vimentin was detected by immunohistochemical analysis in all patients. However, in clear cell areas the expression of α-SMA, laminin, and type IV collagen were mild, while Syn was positive. Moreover, myofibrils and neuroendocrine granules were also present in the cytoplasm of these cells. No C-kit or PDGFR-α genetic mutations were detected in all patients. To conclude, Our results show that GTs in the stomach are histologically and immunophenotypically fully comparable with the glomus tumors of peripheral soft tissues. Neuroendocrine granules and neuroendocrine differentiation were identified in some of the gastric GT cells. Thus, a novel subtype of gastric glomus tumor expressing neuroendocrine cell markers may exist.