Glomus Tumour

About a year ago, the husband of a classmate of mine asked me if I knew the cause of acute pain at a spot on the back of his elbow. When I examined the spot, there was a tiny nodule which was extremely tender. There was no radiation of pain, the elbow joint was normal, there were no tender areas near the medial or lateral epicondyles. It was a very localized lesion in the subcutaneous plane. Although I guessed what it could be I did not give him the diagnosis as the lesion was in an unusual spot. However I told him that he should get it removed as it was very superficial and localized.

He had it removed under a local anaesthetic. Following removal he had total pain relief. Histology confirmed – “A Glomus Tumour”

A Glomus Tumour arises from modified smooth muscle cells of glomus body, a specialized arteriovenous anastomosis involved in thermoregulation. The body regulates its temperature by either increasing or decreasing the blood flow to the hands. The glomus body constrict the arterioles in the hand during cold weather to preserve the body heat and dilate the vessels in warm weather to dissipate the heat.

The tumours are tiny solitary lesions found in the extremities like fingers and toes. When they are outside the nail beds they can be felt as an extremely tender nodule. If they are under the nail bed there may be some discolouration. The patient may present with a history of intense pain at the tip of the finger when holding a glass of ice water. Because it is rare patients often consult many doctors before a diagnosis is established.

Diagnosis is usually based on a good history and physical exam.

The exact incidence of glomus tumor is unknown. They are usually solitary. Multiple tumors are rare and less likely to be painful. A few cases of malignant glomus tumors have been reported; however, they are usually only locally invasive, and metastases are exceedingly rare.

There has been a paper indicating that malignant glomus tumor involving the skin, lungs, jejunum, liver, spleen, and lymph nodes do occur. However they are probably very rare. Solitary glomus tumors, particularly subungual lesions, are more common in females than in males. Multiple lesions are slightly more common in males. Solitary glomus tumors are more frequent in adults. Multiple glomus tumors develop 11–15 years earlier than single lesions; about one third of the cases of multiple tumors occur in those younger than 20 years.

Surgical excision is the preferred method of treatment. Excision is usually curative. Subungual tumours must be carefully removed as they can recur if excision is incomplete.