Pituitary tumor in the elderly
Introduction
Introduction to the elderly pituitary tumor Hypophysoma refers to adenoid cell adenoma, which does not include tumors that occur in the saddle, nor does it include malignant tumors that have metastasized from a distant place to the pituitary. basic knowledge The proportion of illness: 0.001% Susceptible people: the elderly Mode of infection: non-infectious Complications: shock, digestive tract bleeding, hypotension, arrhythmia
Cause
The cause of pituitary tumor in the elderly
Hypothalamic regulation dysfunction (20%):
(1) The hypothalamic polypeptide hormone promotes the proliferation of pituitary cells. After transplantation into the GHRH gene, it can trigger the proliferation of GH cells in rats and further develop into a true pituitary tumor.
(2) The lack of inhibitory factors can also promote tumorigenesis. For example, ACTH adenomas can occur in patients with primary adrenal insufficiency.
Pituitary cell self-deficiency factor (20%):
(1) Pituitary adenomas are derived from a mutated cell, followed by cell replication resulting from monoclonal amplification or self-mutation.
(2) Intervention of external triggering factors or lack of inhibitors:
Defects in 1DA (dopamine) receptor gene expression.
2 The role of oncogenes and tumor suppressor genes: Oncogenes are actually a type of genes involved in the regulation of normal cell growth. Some oncogene products are growth factors and their receptors, while others are involved in the transmission of growth signals in cells. The process, its abnormal expression can lead to abnormal cell proliferation.
Gene mutations or defects in pituitary tumor cells (20%):
The 1Gsa gene mutation has obvious activity due to its mutation and is not found in normal human cells. Therefore, it is called gsp tumor gene (growth stimulating protein oncogene), and gsp gene is found in about 40% of GH adenomas. GH tumors have a characteristic secretion of GH, and there is no normal response to the activity of cAMP system, which is due to the abnormality of G protein stimulant (Gs) linked to adenylate cyclase. This abnormality is a mutation of Gsa gene. That is, the amino acid at positions 201 and 227 of the subunit of the Gs protein has a point mutation, and the mutations thereof all show that the GTPase activity of the Gs protein is inhibited;
The 2ras gene mutation is a mutation in the H-ras gene 12 code, which is related to cell proliferation;
3 The presence of DNA sequence changes in some prolactinomas may result in abnormal expression of the hst (FGF4) gene and mutations in the dopamine receptor D2, but not in normal tissue FGF;
4 It has been confirmed that the loss of the 13th locus (11q13) allele of the long arm of chromosome 11 can cause familial multiple endocrine neoplasia type I (NEN-1) and has been reported in some gonadotropin adenomas and PRL tumors. A deletion of the 11q13 allele was also found, so gene loss at this site may be associated with pituitary tumors.
Recently, the two universities of "pituitary" and "hypothalamus" have been unified to become the two-stage theory of endocrine tumor formation, that is, the occurrence of endocrine tumors can be divided into two phases: induction phase and prolongation, pituitary cells in the induction phase. There are spontaneous or induced genetic mutations that result in abnormal cellular gene expression; subsequent entry into the prolonged phase, under the action of some growth factors or hormones, promotes unrestricted tumor growth.
Prevention
Elderly pituitary tumor prevention
The disease is a malignant disease, and the condition often develops irreversible. The principle of prevention is early detection and early treatment. The purpose of prevention is to delay the progression of the disease, prolong the patient's survival, and focus on and improve those factors that are closely related to our lives, such as smoking cessation, proper diet, regular exercise, and weight loss. Appropriate exercise, enhance physical fitness and improve your disease resistance. Anyone who follows these simple and reasonable lifestyles can reduce their chances of developing cancer.
Complication
Elderly pituitary tumor complications Complications, shock, digestive tract bleeding, hypotension, arrhythmia
Can be complicated by high fever, shock, gastrointestinal bleeding, hypotension, arrhythmia, electrolyte imbalance, lung infections, etc.
Symptom
Pituitary tumor symptoms in the elderly Common symptoms Urine collapse fatigue Cortisol increased amenorrhea galactorrhea
1. Excessive expression of endocrine hormones
In about 70% of cases, the clinical features of the high secretion of the pituitary gland, resulting in a characteristic high-secretion syndrome, such patients are more common in young people, such as amenorrhea - galactorrhea, giant disease and acromegaly, Hypercortisolism, pituitary hyperthyroidism, Nelson syndrome.
2. The pituitary gland itself is under pressure
Pituitary steroids decrease and surrounding target gland atrophy may manifest as symptoms of partial or total hypopituitarism such as fatigue, weakness, hypogonadism or impotence, hypothyroidism, and sometimes tumor compression of the pituitary or hypothalamus may produce a urine collapse disease.
3. The performance of the adjacent tissue of the pituitary adenoma is:
1 headache: may occur early, which is attributed to the increase in the tension of the saddle and the dura mater in the intra-saddle tumor;
2 vision loss, visual field damage, optic nerve compression, bilateral hemianopia may occur;
3 cerebrospinal fluid leakage: the tumor grows downward to destroy the saddle bottom;
4 hypothalamic syndrome: hypothalamic compression can affect sleep, feeding, behavior and emotional changes;
5 cavernous sinus syndrome, eye movement disorders and exophthalmos.
4. Classification
(1) Classification according to cell chromaticity: can be divided into eosinophils, basophils and chromoblastoma
(2) Classification by tumor size:
Grade I microadenomas tumor diameter <10mm
Class II saddle type tumor diameter >10mm
Grade III growth tumor on the saddle >2cm
Grade IV tumor diameter > 4cm
Grade V tumor diameter >5cm
(3) Classified by function:
1 pituitary tumor with secretory function, accounting for 65% to 80% of pituitary tumors:
A. PRL tumor is the most common tumor in pituitary secreting adenoma. In the past, 60% to 70% of cases were considered to be non-functional pituitary tumors. In non-selective autopsy, PRL microadenomas accounted for 23% to 27%, most of which have no evidence of dysfunction before birth.
B. GH tumor is second only to PRL tumor, the disease is more common in young and middle-aged patients, in addition to ACTH tumor, TH tumor, GnH tumor is rare, except for mixed tumor of GH-PRL, most of them are a kind of cell. Form is dominant.
2 non-secretory (non-function) cell tumor: the conventional method to determine serum hormone concentration does not increase, no special clinical symptoms, accounting for 20% to 35% of pituitary tumors, no endocrine function adenoma is the only disease in the elderly, especially in Males have an adenoma with an increasing trend.
Examine
Examination of pituitary tumors in the elderly
1. Endocrine function check:
(1) anterior pituitary function test: the anterior pituitary gland mainly secretes 7 kinds of hormones: growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH), gonadotropin follicle Stimulating hormone (FSH) and luteinizing hormone (LH) should be used for radioimmunoassay of 7 hormones and if necessary, inhibition or stimulation test to understand the function of the tumor, the anterior pituitary involvement, see the function of the anterior pituitary When a section of hypoplasia, chromoblastoma and suspected -subunit pituitary adenoma is suspected, the subunit can be determined. The level of serum subunit in normal humans is 0.5-2.5 ng/ml, and the value of such tumors can be significantly increased. However, in primary hypothyroidism and menopausal women, the alpha subunit level can also be increased by 5ng/ml, which may be related to the increase of TSH, LH and FSH.
(2) Determination of the corresponding target gland hormone: In the case of suspected pituitary tumors, the determination of the target gland hormone should be performed regardless of the secretion function, in order to determine the effect of the hormone on the function and damage of the target gland, such as the adrenal cortex Hormone (PTF) or thyroid hormone (T3, T4) is reduced and should be supplemented before surgery.
(3) Other endocrine function tests: should pay attention to check blood sugar, GH tumor or ACTH tumor may have elevated blood sugar and diabetes, hypoglycemia occurs when the pituitary is significantly stressed, resulting in hypofunction of the anterior pituitary dysfunction, if the saddle area tumor or saddle Large tumors within the body should pay attention to the function of the pituitary gland, and should also pay attention to the presence or absence of parathyroid hyperplasia or adenoma, gastrointestinal and pancreatic tumors and the corresponding hormone changes, in order to exclude the possibility of multiple endocrine adenomas.
2. Vision, visual field examination
Vision and visual field examination are also important. Early detection of visual acuity and visual field damage can help to establish the diagnosis of lesions in the sellar or saddle area. Late stage can help to assess the extent of tumor invasion. Visual acuity and visual field damage are early manifestations of the tumor in the upper saddle area. Typical manifestations are decreased vision, bilateral sacral hemianopia, 1/3 of patients with craniopharyngioma may have primary optic atrophy, optic disc edema is mostly late, but bilateral sacral field defects are not specific for pituitary tumors. Need to pay attention to the exclusion of parasagittal tumors, vascular abnormalities, arachnoiditis and so on.
3. Skull X-ray film
X-ray film on the lateral side of the skull shows that the sella is enlarged, deformed, and spherical. The saddle and saddle bone are compressed and thinned, and there is damage. There may be a double saddle, a pituitary adenoma, and calcification after necrosis, but less See, the saddle and the third ventricle at the third ventricle are the X-ray features of the craniopharyngioma. The pituitary microadenomas often have no manifestations on the skull X-ray.
4. Head CT
The normal pituitary is elliptical in the coronal plane, with a height of 2 to 8.4 mm and a width of 7 to 21 mm. It is divided into 3 types according to the shape of the upper edge: flat, concave and raised, the former two are more common, and the uplift type Common in pregnancy, menstrual period of adolescent women, flattened pituitary density is uniform and brain tissue is equal or slightly higher, can be evenly increased after enhancement.
(1) Large adenoma of pituitary: Most pituitary adenomas are low-density contrast with surrounding normal pituitary tissue, very few have high-density shadows, the upper edge of the pituitary is convex, and the tumor is obviously increased after enhancement. There are necrosis and cysts in the tumor. Sexual change is more clear after the enhancement. When the tumor is larger, the coronal position may indicate that it invades the upper saddle pool, oppresses or invades the optic chiasm, compresses the saddle bottom or breaks into the sphenoid sinus, and invades the cavernous sinus to one or both sides. , acute pituitary apoplexy, CT can be seen in the intratumoral high density shadow.
(2) pituitary microadenomas: sometimes CT is difficult to diagnose, mainly relying on clinical manifestations and hormone determination, enhanced CT signs may be helpful: enhanced pituitary glands have limited low-density areas, sometimes small ring enhancement Nodules; other signs as well as the upper edge of the pituitary, local or unilateral protuberance more meaningful; pituitary height increased, often > 8mm; pituitary stalk offset, saddle bottom local bone thinning, destruction or saddle bottom tilt Etc., in the coronal image, the bottom of the tumor is close to the saddle bottom or the saddle bottom bone abnormalities, mostly pituitary adenomas.
(3) craniopharyngioma: cranial CT is the preferred method, plain scan performance characteristics: saddle area or saddle area tumor, the shape of the saddle area can be irregular, uneven density, can develop to the surrounding normal contour of the saddle upper pool Disappeared, lateral ventricle enlargement, saddle growth can cause saddle bone destruction, calcification is its imaging features, can be multiple round calcification, or linear peripheral calcification, there may be a bundle of areas in the middle of the low-density image.
(4) On the saddle or in the saddle tumor: meningioma is mostly on the saddle, there may be calcification, adjacent bone may be thickened, chordoma often has multiple small calcifications, sphenoid sinus and slope bone destruction in the sellar region Obviously, when the CT of the sellar glioma is flat, the density is uneven, and the low-density shadow is accompanied by punctate calcification. The aneurysms in the sellar region are mostly located on the side of the saddle, which may have obvious bone destruction, and the density is obviously increased after enhancement. .
5. Skull MRI
The MRI signal of the anterior pituitary of normal people is similar to that of gray matter. The 95% of the pituitary gland has a short T1 high signal. The upper edge of the pituitary is mostly concave and flat, a few occasionally flat and slightly convex, and 90% of the local upper convex is pituitary. Micro adenoma, normal pituitary stalk centered, less than 4mm, pituitary stalk displacement is an indirect indication of pituitary lesions. MRI diagnosis of pituitary adenoma is equal to or better than skull CT, can clearly distinguish the relationship between pituitary tumor and optic nerve General MRI diagnosis of pituitary microadenomas is not as good as head CT, but in recent years, the sensitivity of 1.5T high field intensity MRI scan to the diagnosis of pituitary microadenomas has increased to 83%, while the head CT is only 42%, with coronal and sagittal The most common facial image is a focal low signal on the T1-weighted image and a focal high signal on the T2-weighted image. The features are: the upper edge of the coronal pituitary is convex, the height of the pituitary gland is increased, and the saddle bottom Downward bulging, the bilateral internal carotid cavernous sinus segments were asymmetrical, and the lesions were displaced outward and downward. Immediately after the enhancement, the micro-adenomas showed a focal low signal, while the normal pituitary was significantly enhanced.
MRI is not as good as CT in the diagnosis of craniopharyngioma. CT can show typical calcification, while MRI shows poor calcification. The main basis of MRI is: cystic mass in the upper saddle area, enhanced posterior wall Strengthened in a ring shape.
Diagnosis
Diagnosis and diagnosis of pituitary tumor in the elderly
Diagnostic criteria
Hormone determination
2. Imaging examination (CT, MRI) Tumor diameter <5mm, CT is more difficult to find, normal pituitary height 2 ~ 7mm, women such as > 7mm, men > 5mm that there is a tumor.
Differential diagnosis
Empty bubble saddle
Because of the saddle septal defect, the subarachnoid space extends into the saddle to enlarge the sella, the primary is more common in obese women and multi-partum, secondary is seen in surgery, radiotherapy and trauma, infection and spontaneous necrosis of pituitary tumor, After pituitary infarction, the vast majority of patients are asymptomatic, some may have headache, high blood pressure, cerebrospinal fluid rhinorrhea and a small number of pituitary hormone secretion decreased, the lateral sphenoidal X-ray film visible spherical or symmetry increase, skull CT The diagnostic rate reached 100%, which showed that the CT value in the saddle was significantly reduced, and the density was still not seen after the enhancement.
2. Saddle disease
Saddle disease suffers from infection, sarcoidosis, eosinophilic granuloma, aneurysm, meningiomas, hamartoma and metastases. Sometimes the symptoms are easily confused with pituitary tumors, but the lesions on the saddle often have increased intracranial pressure and visual impairment. Hypothalamic syndrome and hydrocephalus, general endocrine manifestations occur after neurological symptoms, CT and MRI help identify, infection, sarcoidosis and other fever and corresponding blood and immune abnormalities.
3. Pituitary enlargement caused by primary target gland hypofunction
Long-term primary hypothyroidism, hypogonadism can lead to weakened negative feedback, increase the secretion of hormones in the pituitary gland, promote the proliferation of hormone-secreting cells, can cause mild increase of the sella, CT and MRI help identify, the corresponding hormone Improvement after replacement therapy also helps identify.
