Glomus tumors are rare soft tissue neoplasms that typically present in adults (ages 20-40 years) as small, blue-red papules or nodules of the distal extremities, with most cases involving subungual sites. These tumors are typically painful, often causing paroxysmal pain in response to temperature changes or pressure. (See Figures 1 & 2)
Glomus tumors are thought to arise from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. Most lesions are solitary and localized to cutaneous sites; however, generalized glomuvenous malformations, or multiple glomangiomas, have also been described, and may have extracutaneous involvement.
While the vast majority of glomus tumors are benign, malignant cases have been rarely reported, with such cases typically being locally invasive, and with metastases being exceedingly rare.