Digital mucinous pseudocysts.

Thirty-one patients with 46 digital mucinous pseudocysts are reviewed. The pseudocysts are usually soft, fluctuant, dome-shaped, dimpled, smooth lesions located near and often associated with a linear defect of the fingernail. Transillumination confirms the diagnosis. Treatment is conservative, usually consisting of intralesional injections. If surgery is necessary, distal interphalangeal joint injection of methylene blue aids in complete removal by identifying the mesothelial-lined pedicle leading from the distal joint to the pseudocyst.