Pea-sized mass on the lef...

A 58-year-old woman complains of having a pea-sized mass on her left wrist's thumb side. She knitted every day for the past several months and felt minor soreness on her wrist. Physical examination reveals a pea-sized ganglion cyst on the extensor pollicis Brevis tendon in the patient. The thumb's flexion and extension move the cyst (Figure).