Glomus Tumour
What is a glomus tumour?
A glomus tumour is a rare, and harmless soft tissue growth. The glomus body is a normal part of the dermal layer of the skin and is thought to aid in temperature regulation. When exposed to cold temperatures, the glomus body moves blood away from the skin's surface to reduce heat loss. While they are located all over the body, glomus bodies are found in higher concentrations in the fingers and toes. Abnormal growth of a glomus body results a Glomus tumour.
Glomus tumours usually occur in people 20 to 50 years of age but are more frequent in young adults. They are more common in women and 70% occur in the hand, mostly underneath the nail bed. Most of the nodules are solitary but they can occur in clusters. Glomus tumours represent 1 to 5% of all soft tissue tumours in the hand and fingers.
What causes glomus tumours?
The cause of glomus tumours is unknown. There are no known risk factors. As these tumours are cold sensitive, they are more commonly diagnosed in cooler climates due to the more prominent symptoms.
What are the signs & symptoms?
Glomus tumours usually present with pain in the finger – under or around the nailbed. They are rarely visible and therefore the diagnosis and treatment are often delayed. There may be subtle blueish discolouration under the nail. Infrequently a small, firm, reddish-blue bump underneath the fingernail can be seen. These lesions are usually quite small, less than 7mm in diameter. They can be extremely painful, are sensitive to temperature change, and very tender with direct pressure. The pain is often worse at night and can be relieved by applying a tourniquet. The mass can cause irregular growth of the nail plate.
How are glomus tumours diagnosed?
These tumours can often be diagnosed with high resolution ultrasound (right). If an ultrasound does not demonstrate the mass, an MRI may be required (below). Gadolinium contrast is often used with MRI to identify tiny glomus tumours as they are highly vascular.
X-rays are usually normal but there can be subtle indentation of the terminal phalanx (bone at the tip of the finger) if the mass has been present for a long time. This is caused by pressure on the bone over time.
Treatment
The treatment involves a minor day surgery procedure performed under general anaesthetic where the nail plate (or part of it) is removed. A small incision made in the nail bed (the soft part under the hard nail plate) and the tumour removed. The nailbed is then repaired with microsurgical stitches. The nail plate may be put back on to protect the nailbed while it heals. The nail plate will fall off but a new one will grow.
A small bandage will be placed on the finger and extend in a triangle over the back of your hand to the wrist. A long acting anaesthetic will keep your finger painfree for 6-8 hours. You will be provided with a prescription for pain relief and a sling.
Risks of Surgery
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Nailbed injury - extremely rare.
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Recurrence of glomus tumour <5%.
Recovery
2 Days: Pain relief may be required, and the hand should be kept elevated to chest height. Driving after 24 hours.
2 weeks: Keep the dressing dry until it is removed by Dr Green at your 2 week post-op check up. You will then be able to get the finger wet. You may wish to cover the nailbed with Coban or a bandaid as the nailbed will be sensitive until the new nailplate grows to cover it.
3 -4 months: The nail plate takes 3-4 months to regrow once and may take up to 3 regrowths (12 months) to look completely normal.