Gill slit cysts can be cancerous, there are no special clinical symptoms, mainly histiocytomorphologic changes, and patients with metastatic foci may have enlarged lymph nodes. Gill slit cyst belongs to congenital disease, due to the development and formation of undegenerated tissues of gill slit, which manifests as a mass in neck or parotid area without tenderness and pressure, gradually increasing in size, and prone to infection. Gill slit cysts may become cancerous, but the possibility is small, and it needs to be clarified by cytological examination by needle aspiration. Gill slit cysts with carcinoma are mainly characterized by histomorphologic changes and rarely have typical clinical manifestations. In patients with metastatic lesions, lymph node enlargement may occur. Patients with gill slit cysts should be examined in a timely manner, and if infection occurs, it needs to be controlled before surgical treatment. Currently, surgical removal of the cyst and fistula is considered the best treatment. Surgery should be performed to remove the lesion as completely as possible, along with the surrounding connective tissue, and if enlarged lymph nodes are found, they should be removed as well. If suspicious lymph nodes are found during surgery, postoperative radiotherapy should be supplemented to prevent the spread of cancer cells. The specific treatment plan should be determined in conjunction with the diagnosis and treatment opinion of specialists.