Retinacular Cysts

Retinacular cysts are small ganglion cysts that typically form on the palm side of the hand at the base of the fingers. These noncancerous lumps develop along the flexor tendons or near the finger joints. Most retinacular cysts are about the size of a pea, but some can grow up to an inch (2.5 cm) in diameter. Their size may fluctuate, often increasing with repetitive hand or finger motion.

Although many retinacular cysts are painless, some can cause discomfort, tingling, numbness, or weakness if they press on a nearby nerve. Depending on their location, they may also interfere with finger movement or grip strength. Retinacular cysts are commonly associated with underlying tendon irritation, such as trigger finger or flexor tendonitis.

The exact cause of retinacular cysts and other ganglion cysts is not fully understood. These cysts form when tissue around a tendon or joint begins to bulge outward, creating a small sac connected by a thin stalk. The sac fills with a thick, gelatinous fluid similar to the natural lubricating fluid found in joints and around tendons.

Several factors may increase the likelihood of developing retinacular or ganglion cysts:

Age and Sex

Ganglion cysts are more common in women between ages 20 and 40, although they can affect anyone.

Osteoarthritis

People with osteoarthritis—especially those with arthritis in the small joints near the fingernails—have a higher risk of developing cysts in nearby areas.

Previous Injuries

A prior tendon or joint injury may weaken the surrounding tissue, making cyst formation more likely.

Repetitive Motion

Activities that involve repetitive gripping or finger flexion may contribute to cyst development or enlargement.

Because retinacular cysts are benign, many can simply be observed—especially if they are small and not painful. When symptoms do occur, several treatment options are available.

Aspiration

For painful or bothersome cysts, your provider may drain the cyst in the office using a small needle and local anesthetic. This procedure is quick, and relief is often immediate. However, some cysts may return over time.

Surgical Removal

Cysts that recur or do not respond to aspiration can be surgically removed. Surgical excision is typically an outpatient procedure done with local anesthesia or light sedation. During surgery, the cyst and a small portion of the adjacent tendon sheath are removed to minimize the chance of recurrence. Most patients resume light hand use shortly afterward, and sutures are removed in about a week. Recurrence after surgical removal is uncommon.