Glomus tumor, NOS
A rare benign or malignant mesenchymal neoplasm arising from cells that resemble the modified smooth muscle cells of the glomus body. The majority of glomus tumors occur in the distal extremities.
Gastric glomus tumors are also rare and occur in adults, especially women. It usually presents as a 2–5 cm intramural mass with symptoms similar to those of gastric gastrointestinal stromal tumour (GIST)
. Histological and immunohistochemical features are similar to those of peripheral glomus tumours. Features that are specific to gastric glomus tumours include plexiform growth within the muscular propria and vascular involvement. The latter has no adverse prognostic significance. Immunohistochemically, there is strong expression of SMA and pericellular laminin/collagen IV, but no KIT, DOG1/ANO1, CD34, or desmin. Focal synaptophysin positivity is not uncommon and should not lead to mistaken diagnosis of a neuroendocrine tumour. Most glomus tumours are benign, but metastasis has been reported in a tumour of > 5 cm in size with mitotic activity
Appelman HD, Helwig EB (1969)
Glomus tumors of the stomach.
Cancer 23: 203-13
Miettinen M, Paal E, Lasota J, Sobin LH (2002)
Gastrointestinal glomus tumors: a clinicopathologic, immunohistochemical, and molecular genetic study of 32 cases.
Am J Surg Pathol 26: 301-11