Glomus tumour: the immunohistochemical characteristics of twenty-three cases.

Twenty-three cases of glomus tumour were investigated with the antibodies keratin, vimentin, neurofilaments, desmin, actin, S100, Factor VIII-related antigen, substance P and KP1/CD68. It will be shown that the glomus cells were vimentin-positive in 11 out of 23 cases (48%), actin-positive in 16 out of 23 cases (70%) and desmin-positive in 9 out of 23 cases (39%). The KP1 monoclonal antibody demonstrated the presence of numerous mast cells in some cases. The substance P was only occasionally positive in six cases (26%). No positive staining was seen with keratin, neurofilaments, S100 and Factor VIII-related antigen. It is confirmed that glomus cells can be considered as elements of smooth muscle origin. Our study suggests a possible explanation of the mechanism which induces paroxysmal attacks in patients with glomus tumours.