Tumors that occur in the parenchymal cells of the pineal gland include pineal cell tumors and pinealoblastomas. The majority of what used to be called pineal tumors are germ cell tumors or atypical teratomas, while true pineal cell tumors are rare. There is a wide age range, with pineal cell tumors being more common in adults and pinealoblastomas in children. The rate is basically equal between male and female. Clinical manifestations 1.increased intracranial pressure The tumor protrudes to the posterior part of the third ventricle and obstructs the superior port of the aqueduct, or the aqueduct is narrowed or atretic due to the development of the anterior and inferior parts of the aqueduct, resulting in early clinical manifestations of obstructive hydrocephalus and increased intracranial pressure, such as headache, vomiting, fundus edema and altered state of consciousness. 2.Neurological symptoms â‘ Ocular signs: tumor compression on the superior colliculus of the tetrahymena may cause eye movement disorder, pupil dilatation or unequal size, etc. (2) Hearing impairment: If the tumor is large, it may compress the inferior colliculus of the tetrahymena and the medial geniculate body and cause bilateral tinnitus and hearing loss. â‘¢Cerebellar sign: The tumor may compress the superior cerebellar peduncle and superior part of the cerebellum, so trunk ataxia and nystagmus may appear. (4) Subthalamic damage: It may be caused by the direct invasion of the tumor or disseminated planting to the lower thalamus, or the tumor may cause the obstruction of the aqueduct and the expansion of the anterior part of the third ventricle and affect the lower part of the optic thalamus. The normal pineal gland can secrete melatonin, which can inhibit the function of the pituitary gland and reduce the content and secretion of gonadotropin in the pituitary gland, while the function of the pineal gland is active in children and prepubertal period, thus inhibiting the premature development of sex characteristics, and the pineal gland gradually degenerates at puberty to make the development of sex characteristics mature. The delayed development of sex characteristics can be seen in pineal tumor patients with pineal cell tumor. Due to the increase of intracranial pressure and direct compression of the midbrain by the tumor, some patients may have seizures, pathological reflexes and even impaired consciousness. In patients with ventricular shunts, tumor cells may metastasize along the shunts to distant areas. The tumor may appear as a low density, isometric mixed density or homogeneous slightly high density lesion on CT scan. The tumor may appear as a round-like lesion with clear border, and there may be scattered small calcification foci, bilateral lateral ventricles and the anterior part of the third ventricle are enlarged, and if there is ventricular canal or subventricular metastasis, the band around the lateral ventricles and the third ventricle on both sides is slightly high density lesion, and there may be uniform contrast enhancement. 2.MRI examination The tumor is isosignal in T1-weighted image, or low signal, and high signal in T2-weighted image. Sagittal scan can help to understand the growth direction of the tumor and the degree of midbrain compression, and Gd-DTPA enhancement is also uniform enhancement. Treatment and prognosis The treatment of pineal cell tumor should be mainly surgical, because the tumor is not very sensitive to radiation therapy due to its pathological nature, and in some patients, although the intracranial pressure is not high after ventricular shunt, the signs of midbrain compression are more obvious. According to the direction of tumor development, different surgical approaches should be used, mainly the trans-Poppen approach and the intercallosal vault approach. If the tumor is not completely resected and the cerebrospinal fluid circulation obstruction is not released, the lateral ventricular to ventral shunt surgery should be performed in time.