Glomus tumor originating within a digital nerve.

Glomus tumors are thought to arise from specialized cells normally found within the glomus apparatus of the dermal stratum reticularis. We report the unusual occurrence of a glomus tumor from within a peripheral nerve. Previous investigators have suggested that the rare occurrence of glomus tumors in tissue where the glomus apparatus has not been described arise from ectopic glomus cells or differentiate from nonglomus cell sources. Many of the "ectopic" glomus tumors have been found in regions of extensive arteriovenous shunting such as in the digestive system and lung suggesting the presence of glomera at these locations. The finding of a glomus tumor within a peripheral nerve, a region where extensive arteriovenous shunting and glomus bodies have not been described, supports the occasional origin of a glomus tumor from a nonglomus cell source.