Practice Essentials
Glomus tumors are benign hamartomas originating from the glomus body. [1] The glomus body is a neuromyoarterial apparatus composed of vascular structures, nerve cells, and smooth-muscle cells. It is found in the dermis throughout the body, with the highest concentrations being in the hands and feet. The glomus body is responsible for thermoregulation.
Wood first described the clinical findings associated with glomus tumor in 1812. He presented cases of painful subcutaneous nodules that were characterized by pain and temperature sensitivity and that were curable with excision. [2]
Pain is the usual presenting symptom of a glomus tumor. Patients also have temperature sensitivity, especially when they are exposed to cold. The classic triad of sensitivity to cold, pain, and point tenderness is not always found.
Local soft-tissue tenderness and thickening may be present. A mass is sometimes detectable in the area of tenderness. On clinical examination, a positive result with the Love test and the Hildreth sign suggest the diagnosis.
Because the diagnosis of glomus tumor is primarily clinical, laboratory workup usually is not needed. If the diagnosis is uncertain in view of the patient's history and physical findings, imaging studies are warranted.
Surgical excision of the tumor is the mainstay of treatment. Pain relief should be provided until the procedure is performed. Excision should be limited to symptomatic lesions. Sclerotherapy and laser treatment have been used to destroy the tumor as therapeutic alternatives to surgical excision.
Pathophysiology and Etiology
In a glomus tumor, elements of the normal glomus body, vascular structures, nerve cells, and smooth-muscle cells are affected by marked hypertrophy, which leads to a nodulelike structure. The lesion sometimes appears as a locally enlarging mass. No evidence of mitosis is observed in the structure.
A few case reports have described glomus tumors possessing malignant potential. [3, 4, 5, 6] Findings have included the following:
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Large size
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Deep location
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Infiltrative growth
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Mitotic activity
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Nuclear pleomorphism
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Necrosis
Some reports have mentioned metastases and death from the disease. Glomangiosarcoma is a rare malignant variant that may metastasize.
No risk factors for the formation of glomus tumors are known.
Epidemiology
Glomus tumors are rare. Congenital, familial, and multiple lesions are extremely rare. [7] The incidence of multiple tumors is 25%. [8]
Glomus tumors are most commonly found in distal extremities in the nail bed and subcutaneous tissues of the distal phalanx. About 75% of glomus tumors occur in the hand, and 60% are subungual. [9, 10, 11] Other sites include the wrist, forearm, [12] and foot, [13] but the tumor can occur anywhere in the body.
Glomus tumors have also been described at unusual sites, such as the patella, tendons, bone, eyelid, nasal cavity, stomach, colon, rectum, kidney, and cervix. [14, 15, 16, 17] Intraosseous glomus tumors, which arise from bone, are similarly rare: Only about 20 cases of glomus tumor in bone have been reported in the literature. [18, 19, 20, 21, 22, 23]
Glomus tumors mostly occur in middle age, especially in the fourth and fifth decades of life. However, they have been described in all age groups. No clear sex predilection has been reported for glomus tumors in general; however, subungual glomus tumors appear to be more common in women than in men.
Prognosis
The outcome after complete excision with removal of the fibrous capsule is usually excellent, and pain relief occurs immediately after surgery. [24] Recurrences are rare if the capsule is completely excised.
In a retrospective multicenter study that included 72 patients with surgically excised digital glomus tumors (mean follow-up, 5.4 years), Kim et al investigated risk factors for recurrence and assessed complication and recurrence rates according to surgical approach and method. [25] At final follow-up, recurrence was observed in 6.9% of patients and postoperative complications in 12.5%. Recurrence rates were higher, though not significantly so, in a group with pulp lesions treated via a direct approach and in a surgical loupe group. A nail-sparing approach and microscopic excision did not reduce nail deformities. No significant predictors of recurrence were identified.
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Glomus tumor.
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Subungual hue seen with a superficial glomus tumor.
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Intraosseous glomus tumor appears as a bright, well-delineated mass on a T2-weighted MRI.
