Typical case: A young male patient, 32 years old, was admitted to the hospital mainly because of “headache with nausea and vomiting for 3 months, aggravated by unsteadiness in walking for 1 month, previously healthy. Physical examination: clear consciousness, weak spirit, answers to tangential questions, both pupils are equal in size and round, 3 mm in diameter, sensitive light response, facial symmetry, tongue extension in the center, soft neck, no resistance, normal limb sensation, muscle strength grade V, low muscle tone, pathological signs not elicited, poor ataxia, unstable walking, positive Romberg’s sign. External cranial MRI: ventral occupying lesion of the brainstem, nature to be diagnosed. Preoperative MRI: The patient was admitted to the hospital and underwent surgery after perfecting the preoperative examination. The surgery was performed by left distal lateral approach tumor resection. The patient recovered well after surgery and was discharged 2 weeks after surgery. The patient has recovered well after surgery for six months.