Craniopharyngioma and pituitary tumor are two common tumors in the saddle area, and many patients are still difficult to be diagnosed after visiting several hospitals. Guo Hongchuan, Department of Neurosurgery, Xuanwu Hospital, Capital Medical University 1. What are the differences between the symptoms and signs of craniopharyngioma and pituitary tumor? Endocrine abnormalities in pediatric craniopharyngioma are mainly manifested by delayed growth and sexual maturity, while in adult craniopharyngioma endocrine abnormalities are firstly manifested by hypothyroidism and some hypopituitarism (male dysfunction, female weakness and loss of appetite), but both adults and pediatric patients can have the manifestation of polyhydramnios and polyuria; while functional pituitary adenoma must show symptoms of increased secretion of related pituitary hormones The symptoms of functional pituitary adenomas are: (1) thick hands and feet, large nose and thick lips (growth hormone type), (2) thin hair and delicate skin in men, and menopause and lactation in women (prolactin type), (3) full moon face, buffalo back, and purple skin discoloration on the back of the abdomen (adrenocorticotropic hormone type). However, both craniopharyngioma and pituitary tumor can be associated with vision loss, visual field defects and headache and dizziness. 2. What is the difference between the two in terms of tumor growth sites? Because of the different origins of craniopharyngioma and pituitary tumor, there are slight differences in the growth sites: most craniopharyngiomas are located above the saddle diaphragm because they originate from the pituitary stalk, and giant craniopharyngiomas often invade the lower part of the optic thalamus or even the third ventricle. The pituitary adenoma originated from the adenohypophysis and is mostly confined to the saddle by the saddle diaphragm, but the pituitary macroadenoma can break through the saddle diaphragm and grow upward or break through the saddle base to fill the pterygoid sinus cavity, and the invasive pituitary adenoma can invade both cavernous sinuses and even encircle the internal carotid artery. Craniopharyngioma itself has no endocrine function, but due to the compression of important structures such as pituitary stalk and hypothalamus, it is often accompanied by low A-5 and cortisol, and even low levels of several hormones due to hypopituitarism, and a few sodium and potassium ion disorders due to polyhydramnios; while functional pituitary adenoma has elevated growth hormone, prolactin and cortisol according to the three types, and a few non-functional pituitary adenomas have elevated growth hormone, prolactin and cortisol due to hypopituitarism. 4. How can MRI differentiate these two types of tumors? Craniopharyngioma is divided into solid, cystic and cystic-solid structures, and the normal pituitary gland in the saddle is mostly visible in the sagittal position of the enhanced MRI, while the cystic structure has a thick wall with circumferential enhancement (post-stroke liquefied pituitary adenoma must not have a thick wall with circumferential enhancement); pituitary tumor is mostly solid and has a uniform signal, while stroke pituitary tumor has a mixed signal and most of the normal pituitary gland disappears on MRI. Can CT of the skull base help to differentiate between these two tumors? Is pathological examination necessary? However, not all calcifications are craniopharyngioma. Very few pituitary tumors with bone metaplasia in the saddle area may also show calcifications on CT of the skull base. Pathological examination after surgical treatment is necessary, and pathological diagnosis is still the currently accepted gold standard.6. What tests are needed to diagnose craniopharyngioma? The following tests are usually required to diagnose craniopharyngioma: MRI plain plus enhancement of skull base, CT of skull base, endocrine and serological examinations, visual field and fundus examination, etc. In addition, medical history questioning and detailed physical examination by a doctor with rich clinical experience are no substitute for any ancillary examinations.