Glomus tumor epidemiology and demographics

Frequency
United States: The exact incidence of glomus tumors is unknown. The multiple variant is rare, accounting for less than 10% of all cases. The probable misdiagnosis of many of these lesions as hemangiomas or venous malformations also makes an accurate assessment of incidence difficult.

Mortality/Morbidity
The most common adverse effect is pain, which is usually associated with solitary lesions. Multiple tumors are less likely to be painful. In one report, a patient with more than 400 glomus tumors had thrombocytopenia as a result of platelet sequestration (ie, Kasabach-Merritt syndrome). Malignant glomus tumors, or glomangiosarcomas, are extremely rare and usually represent a locally infiltrative malignancy. However, metastases do occur and are usually fatal.

Sex
Solitary glomus tumors, particularly subungual lesions, are more common in females than in males. Multiple lesions are slightly more common in males.

Age
Solitary glomus tumors are more frequent in adults than in others. Multiple glomus tumors develop 10-15 years earlier than single lesions; about one third of the cases of multiple tumors occur in those younger than 20 years. Congenital glomus tumors are rare; they are plaquelike in appearance and are considered a variant of multiple glomus tumors.