Glomus tumors and neurofibromatosis: A newly recognized association

Background: Glomus tumors are painful benign tumors arising from the neuromyoarterial elements of the glomus body, typically in a subungual location. Historically, glomus tumors have been considered isolated or sporadic, not typically associated with other disease processes. Over the last few years, however, multiple case reports, a molecular genetics study, and an epidemiologic study have confirmed an association between type I neurofibromatosis and glomus tumors. The purpose of this review is to summarize the existing information about the association between neurofibromatosis and glomus tumors and to determine whether glomus tumors that are associated with neurofibromatosis differ from isolated glomus tumors in terms of tumor number, location, and sex distribution. Methods: A PubMed, Ovid Medline, and Cochrane Database search was performed using the terms “glomus tumor,” “glomus tumour,” and “glomangioma” each combined with the search term “neurofibromatosis.” Fifteen English language articles were included. Information about the molecular genetics, patient sex, number of tumors per patient, and tumor location were recorded. Results: A total of 36 patients with glomus tumors and neurofibromatosis have been reported in the literature. Seventy-nine percent were female. Tumors were multifocal in 32% of patients, with an average of 1.4 glomus tumors per patient. Glomus tumors arose in a nonsubungual location in 38% of patients. Conclusions: A strong association between type I neurofibromatosis and glomus tumors has been identified. In neurofibromatosis patients with glomus tumors, the sex distribution, tumor location, and tumor burden appear similar to those in patients with isolated glomus tumors. Treating providers should be aware of this association to facilitate prompt diagnosis and treatment.