A case of mucous retention cyst in the middle of the floor of the mouth

A rare case of mucous retention cyst in the middle of the oral floor is reported. A 63-year-old woman was referred because of a painless swelling in the middle of the oral floor, which had persisted for 1 month. Resection was performed. The mass was located between the genioglossus muscle and geniohyoid muscle and was unrelated to the sublingual gland or Warthon's duct.The histopathological diagnosis was solitary mucous retention cyst. Differential diagnosis is also discussed.