Mycoid Cyst

Also known as a Digital Mucous Cyst

A mucoid or myxoid cyst is a benign, typically pain-free lump found near a nail or joint margin. They can often be mistaken for a blister due to the serous exudate (clear fluid) underlying the skin.

As you can see in the photos, a common place the cyst is found is at the distal interphalangeal joint at the toe. They are likely caused by joint degeneration such as osteoarthritis whereby the synovial fluid leaks out of the joint space and causes a fluid build-up out of the joint area. These types of cysts can also be caused by the fibroblast cells in connective tissue producing too much mucin.

Signs and symptoms

The myxoid cyst is usually pain-free but can cause rubbing on the adjacent digits or in shoes. The cysts are smooth, located near a joint, and skin coloured with a red or blue tinge and can often look like a “pearl”.

Often people believe the cyst is a blister and will pop them. The myxoid cyst is quick to re-develop!

Treatment

The myxoid cyst very rarely resolves on it’s own. The can be regularly cleaned and fluid aspirated by your Podiatrist but they will likely return. Other treatment options are cryotherapy, steroid injections or surgery.

Surgery involved removing the cyst entirely. The surgeon will inject a dye to find the fluid leak, then proceed to seal the area. Surgery has a higher than 90% success rate.