myxoid cyst myxoid cyst a myxoid cyst is a cutaneous condition often characterized by nail plate depression and grooves. "mucous cyst" redirects here. for swelling of connective oral tissue, see oral mucocele. myxoid cystother namesdigital mucous cyst, and mucous cyst)digital mucous cyst in left index finger with nail depressionspecialtyoncology, rheumatology, orthopedic surgery