The lesions present most frequently during the fourth and fifth decade of life although they can be found in any age and at any site. The subungual tumors affect women three times more commonly than men.
Clinically, glomus tumors are characterized by a triad of sensitivity to cold, localized tenderness and severe intermittent pain. The pain can be excruciating and is described as a burning or bursting. The exact cause of the pain is not completely understood, but nerve fibers containing the pain neurotransmitter substance P have been identified in the tumor.
Radiologically, glomus tumors appear as well circumscribed osteolytic lesions. The lesion shows either bone erosion or invasion depending on where it arises. A sclerotic border is present due to the slowly enlarging
CT scan shows a non-specific subungual or soft tissue mass. T1 MRI is not as useful for subungual lesions as it only demonstrates a dark, well delineated mass. Glomus tumors appear as a very high and homogeneous signal intensity on T2 weighted images. MRI is useful for the detection of lesions in the soft tissues. The radiological differential includes epidermal inclusion cyst, enchondroma, chronic osteomyelitis, sarcoidosis, metastatic carcinoma, subungual melanoma and osteoid osteoma.
Treatment of glomus tumors consists of surgical excision. Repair of the nail bed must be performed after the removal of subungual lesions.