Bone change after surgical treatment of mucous cyst at the interphalangeal joint of the great toe in a patient with rheumatoid arthritis

Digital mucous cysts are a type of benign cysts of the digits, typically located at the distal interphalangeal joints or in the proximal nail fold, which usually occur on the hands. The diagnosis of digital mucous cysts is relatively easy because of its light-transmitting property, but the treatment is often difficult because of complications including recurrence, infection, diminished range of motion, and nail deformity. We report a case of rheumatoid arthritis (RA) showing good course after surgical treatment of mucous cyst at the interphalangeal joint of the great toe. In a case of RA, combination of synovectomy with surgical treatment of mucous cyst might be effective.