Glomus tumours. An immunohistochemical study.

The histological and immunohistochemical features of 20 glomus tumours (glomangiomas) were studied retrospectively in routinely processed material. The tumours came from 18 patients (9 women and 9 men, aged 25 to 80 years); two were recurring lesions. Twelve were classified as solid glomus tumours, eight as glomangiomas. Small nerve fibres were present in all except one. A variable number of mast cells were found in the stroma. The glomus tumour cells were negative when stained for Neuron-Specific Enolase, Glial Fibrillic Acidic Protein, S-100 Protein, Chromogranin, or with the Ulex Europaeus Lectin type 1. Conversely, all were found to be positive for Actin, Myosin, and Vimentin. Four exhibited an equivocal reaction for Desmin, the rest were negative. This immunohistochemical profile is in accordance with the findings of other investigators and can be helpful in differential diagnosis. It also shows the glomus cell to be related to smooth muscle cells and pericytes. The majority of these lesions are probably hamartomas, but a few may be true neoplasms.