Tender masses that appear in the palm by the base of a finger are usually retinacular cysts. Retinacular cysts are simply ganglion cysts that come from the flexor tendon sheath of the finger. Retinacular cysts often lead to pain when gripping objects. Fortunately, they are benign and easily treated.
Initial treatment is by aspiration with a needle, removing the fluid from the center of the cyst. If the cyst’s walls are thin, the cyst will disappear. If the walls of the cyst are thick, a smaller, less tender mass may still be palpable. If the aspiration doesn’t change the cyst at all, then the mass is probably not a cyst, and an MRI and possible surgical excision should be considered.
Aspiration is usually successful in treating retinacular cysts. However, as for ganglion cysts elsewhere, once a cyst recurs, further aspirations will probably not be effective treatment. If a retinacular cyst returns following a successful aspiration, then the options are to live with it or have it removed surgically.
Fortunately, the surgery is a quick outpatient procedure. The cyst is removed along with a section of the flexor tendon sheath from which it originated (Retinacular Cyst Excision Picture). The section of the sheath is removed in order to prevent recurrence, which is rare if this step is performed. This is similar to removing a section of joint capsule when excising ganglion cysts (please see the Wrist’s ‘Ganglion Cyst’ section).
After surgery, keep the wound clean and dry for 24 hours. There are no stitches to remove (they’re buried and absorbable). There’s a piece of tape over the wound. The tape will fall off when it’s ready. The longer it stays on, the nicer the final wound may look. Please don’t submerge the incision under water (like swimming, or putting your hand under water) for 10 days after surgery. There’s a piece of special tape over the wound. The longer it stays, the nicer the wound will look. It’ll fall off when it’s ready. There are no stitches to remove. I recommend avoiding heavy activities like lifting and gripping for 4 weeks after surgery, in order to minimize post-operative pain.
In conclusion, tender masses near the junction of a finger and the hand are often retinacular cysts, which are easily curable by experienced hand surgeons.