Salivary gland mucous cysts include minor salivary gland mucous cysts and sublingual gland cysts, which can be categorized into extravasation cysts and retention cysts according to the etiology and pathological manifestations, with the former accounting for the majority. Then how to check the mucus cyst? CT examination 1, according to the history of diagnosis. 2, the surface is only covered with a thin layer of mucous membrane, so it is translucent, light blue vesicles, similar to blisters. The texture is soft and elastic. Classification 1.Mucous cysts are found on the ventral side of the lower lip and tongue tip. Cysts are located under the end of the year, the surface is only covered with a thin layer of mucous membrane, so it is translucent, light blue vesicles, similar to blisters. The texture is soft and elastic. The cyst is easily bitten and ruptured, and the egg-white transparent viscous liquid is discharged, and the cyst disappears. After the rupture place heals, it is filled with mucus and forms a cyst again. Sublingual gland cysts are common in adolescents and can be divided into 3 categories: (1) Simple type: accounting for the majority. The cysts are located in the sublingual region, light purple-blue color, soft and fluctuating sensation when touched. It is often located on the side of the floor of the mouth. Larger cysts can lift the tongue, resembling a “heavy tongue”. After rupture of the cyst due to trauma, a viscous and slightly yellow or egg-white-like fluid flows out, and the cyst temporarily disappears. The window heals after the summer, and the cyst grows as before; (2) extra-oral type: also known as latent type. The main manifestation is a swelling in the submandibular region, while the cyst in the floor of the mouth is not obvious. It is soft to palpation, has no adhesion to the skin, and is not compressible. (3) Dumbbell type: a mixture of the above two types, i.e., cystic masses are seen in both the intraoral sublingual area and the extraoral mandibular area.