Glomangiomas, also known as glomus tumors, are benign vascular tumors typically seen at the distal extremities. On imaging, they characteristically present as small hypervascular nodules under the fingernail.
These tumors should not be confused with paragangliomas, which are sometimes also referred to as glomus tumors.
It classically presents in young to middle-aged (4 to 5 decades ). There is a recognized female predilection. They can be multiple in ~ 10% of cases. Glomus tumors account for 1-5% of the soft-tissue tumors in the hand .
The lesion usually presents as a small firm red-blue nodule under the fingernail and is exquisitely painful. Sometimes the pain is worse at night; it may disappear when a tourniquet is applied.
May also present as hemorrhage under the nail. The presence of the Hildreth sign (pain relief following the application of a tourniquet proximally) is considered pathognomonic on clinical grounds .
Glomus tumors originate from the neuromyoarterial plexus: modified smooth muscle cells of the glomus body. They are best thought of as hamartomas rather than true tumors. There are two main components on microscopy:
- branching vascular channels
- aggregates of specialized glomus cells
Approximately 75% occur in hand ; asubungual position is characteristic.
- the tumor is difficult if not impossible to identify, rarely can be seen as a subtle soft tissue density
- may show a marginated osseous erosion or thinning of the adjacent cortical bone
- subungual hypoechoic nodular lesion at the region of maximum tenderness
- hypervascularity on Doppler tends to be prominent
Signal characteristics include:
- T1: low to intermediate signal
- T1 C+(Gd): shows avid contrast enhancement (usually uniform) due to high vascularity
- T2: intense high signal
Treatment and prognosis
Treatment is surgical resection.
General imaging differential considerations include:
- paraganglioma (also sometimes called glomus tumor)
- glomus body
- Riesenzelltumor der Sehnenscheiden
- non chromaffin paragranglion cells