Pituitary Disorders PowerPoint Presentation PDF

# Pituitary Disorders ## Description A presentation on pituitary disorders by Dr Hozifa Hussein. ## Pituitary Gland - The pituitary gland is a small gland that sits at the base of the brain. It releases hormones that control many important bodily functions, including: - Growth - Reproduc...

# Pituitary Disorders ## Description A presentation on pituitary disorders by Dr Hozifa Hussein. ## Pituitary Gland - The pituitary gland is a small gland that sits at the base of the brain. It releases hormones that control many important bodily functions, including: - Growth - Reproduction - Metabolism - Blood pressure - Pituitary disorders can be caused by either too much or too little of the hormones produced by the pituitary gland. ## Hypopituitarism - Hypopituitarism is a rare disorder where there is a loss of function in the pituitary gland. This results in the failure to secrete hormones that affect many of the body's functions. - Patients diagnosed with hypopituitarism may be deficient in one or several hormones or have complete pituitary failure. ### Etiology - Congenital - Tumor - Inflammation - Infection - Head injuries - Lesions - Surgery - Tuberculosis - Radiographic therapy ## Dwarfism - Dwarfism is an endocrine disorder resulting from hyposecretion of growth hormone during the critical development period in children. - The term "short stature" or "little people" is often used as well. ### Types - **Proportionate:** The body is proportionate, but people are small in stature. - **Disproportionate:** Short limbs are smaller in proportion to the trunk. - **Asymmetry:** The body is not symmetrical. ### Causes - Reduction in GH secretion in infancy or early childhood causes dwarfism. This can occur due to: - **Tumor of chromophobes:** These tumors compress and destroy the normal cells that secrete GH. - **Deficiency of GH-releasing hormone:** This hormone is secreted by the hypothalamus. - **Deficiency of somatomedin C:** This hormone is also important for growth. - **Atrophy or degeneration of acidophilic cells:** These cells are located in the anterior pituitary. - Lesion of the anterior pituitary due to infection or injury - Genetic disorders. - Hereditary. - Lesion of the hypothalamus resulting in hyposecretion of growth hormone releasing factor. ### Clinical Features - Stunted physical and skeletal growth. - The average height is 4 feet or less than that. But dwarfism could apply to an adult who is less than 4 feet 10 inches tall. - Low blood glucose level. - Normal development of gonads. - Normal IQ. ### Diagnostic Evaluation - History collection. - Physical examination. - CT scan, MRI scan of brain. - Blood test - to rule out hormone level. ### Management - Dwarfism's treatments don't increase stature but may alleviate problems caused by complications. - Surgical procedures may correct problems with bones in people with disproportionate dwarfism. - Some people with dwarfism elect to undergo limb-lengthening surgery. - Growth hormone deficiency is treated with injections of a synthetic version of the hormone. ## Hyperpituitarism - Hyperpituitarism is the excessive production of growth hormone. - Hyperpituitarism is a chronic, progressive disease marked by hormonal dysfunction and startling skeletal overgrowth. - Hyperpituitarism appears in 2 forms: - **Gigantism:** Affects infants and children. - **Acromegaly:** Affects adults after epiphyseal closure. ## Gigantism - The pituitary gland secretes growth hormone (GH), which is responsible for overall body development during childhood - When too much growth hormone is secreted that augments the growth of muscle, bones, and connective tissue in childhood or adolescence before the end of puberty, the condition is called Gigantism. - The result is an increase in height and formation of additional soft tissues. - Some individuals may achieve a height in excess of eight feet. ### Etiology - In most of the cases, noncancerous pituitary gland tumors are behind gigantism. - Genetic mutation. - **McCune-Albright syndrome:** A disorder that causes unusual growth of bone tissues, gland irregularities, and patches of light-brown skin. - **Carney complex:** A hereditary condition that may include cancerous or noncancerous endocrine tumors and spots of darker skin. - **Multiple endocrine neoplasia type 1:** A hereditary condition that causes tumors in the pancreas, parathyroid glands, and pituitary gland. - **Neurofibromatosis:** A hereditary disease that causes tumors in the nervous system. ### Clinical Features - The child will be much taller than other children of the same age. - Parts of the body may be visibly bigger than other parts. **Common signs of gigantism include:** - Large hands and feet. - Thick toes and fingers. - A bulging jaw and forehead. - Improper facial features. - Children suffering from gigantism may also suffer from large heads, lips, or tongues. The symptoms of gigantism depend on the size of the pituitary gland tumor. - Some children may experience vision problems, headaches, and nausea from the tumor. **Other Symptoms:** - Large-scale sweating - Weakness - Onset of puberty may be delayed in boys and girls - Irregularity in the menstrual cycle - Deafness ### Diagnostic Evaluation - History collection. - CT scan, MRI scan - to rule out pituitary tumor. - Oral Glucose Tolerance Test - to rule out hyperglycemia. - Blood test - to rule out growth hormone level, high prolactin level, increased insulin level, and growth factor 1 levels. ### Management - Gigantism requires early detection and strong treatment to prevent excess production of growth hormone and to improve life expectancy. - **Surgery:** - **Transsphenoidal Adenectomy** - **Hypophysectomy:** Surgery is the first line of treatment with the objective of removing the tumor to minimize growth hormone levels and reduce the pressure on the nerves. - **Radiation therapy:** Another option of surgery has not provided a complete cure. It can take several years for radiation therapy to be effective - **Drug therapy**: - **Prior to surgery:** To control symptoms and cause the tumor to shrink. - **Post surgery:** When growth hormone levels are not managed. - **While radiation therapy is going on.** - **Individuals not qualified for surgical process.** - Regular medical follow-up is required to scrutinize growth hormone and insulin-like growth factor 1 to notice any growth of the tumor. ## Acromegaly - Acromegaly is a chronic metabolic disorder in which there is a secretion of too much growth hormone and the body tissues gradually enlarge. ### Incidence - It occurs in about 6 of every 100,000 adults. - Occurs in adulthood, usually during middle age. ### Etiology - **Pituitary tumor:** - Benign tumor. - Adenoma of the pituitary gland. - **Non-pituitary tumor:** - Benign or cancerous tumor of the other part of the body such as lungs, pancreas, and adrenal glands. **Excess growth hormone and growth hormone releasing factor in the blood leads to changes in the physical appearance and functions of the body.** ### Symptoms - Hand swelling, "sausage-like" fingers. - Increased shoe size. - Diaphoresis. - Thickening of the facial features, especially the nose. - Increased prominence in the jaw and forehead. - Thickened skin. - Swelling of the tongue. - Thickening or swelling of the neck. - Arthritis. - Sleep apnea. - Headache. - Partial loss of vision. May occur in one eye or both eyes. - Pain, numbness, tingling, or weakness in the hands and wrists. - Increased thirst and urination. - Hyperglycemia. - Chest pain. - Shortness of breath. - Palpitation. - Heart failure. ### Diagnostic Evaluation - History collection. - Physical examination. - CT scan, MRI scan of the head, chest, abdomen, pelvis, adrenal glands, ovaries. ### Management - The goal of the treatment is to relieve and reverse the symptoms of acromegaly. - **Surgical treatment:** The first line of treatment. Surgery brings remission in some people but not all. - **Transsphenoidal Hypophysectomy** - **Radiation therapy:** An option to reduce the size of the tumor and, hence, reduce the production of growth hormone. - Radiation therapy focuses on high intensity radiation at pituitary tumors to destroy the abnormal cells. - Given in 2 forms: External beam and stereotactic. - **Drug therapy:** - **Somatostatin analogs:** Reduce growth hormone release. - **Dopamine agonists:** Prevent the release of growth hormone. - **Growth hormone receptor agonist eg Pegvisomant:** Blocks the effects of growth hormone. ## Diabetes Insipidus - Diabetes insipidus is a disorder of the posterior lobe of the pituitary gland characterized by a deficiency of antidiuretic hormone (ADH), also known as vasopressin. - **Great thirst (polydipsia) and large volumes of dilute urine characterize the disorder.** ### Types - **Central diabetes insipidus** - **Nephrogenic diabetes insipidus** - **Psychogenic diabetes insipidus** - **Gestational diabetes insipidus** ### Causes - **Central diabetes insipidus:** - Head trauma or surgery - Pituitary or hypothalamic tumor - Intracerebral occlusion or infection - **Nephrogenic diabetes insipidus:** - Systemic diseases involving the kidney - Multiple myeloma - Sickle cell anemia - Polycystic kidney disease - Pyelonephritis - Medications such as lithium. ### Pathophysiology - **Central diabetes insipidus:** - Loss of vasopressin-producing cells. - Causing deficiency in antidiuretic hormone (ADH) synthesis or release. - Deficiency in ADH, resulting in an inability to conserve water. - Leading to extreme polyuria and polydipsia. - **Nephrogenic diabetes insipidus:** - Depression of aldosterone release, or inability of the nephrons to respond to ADH. - Causing extreme polyuria and polydipsia. ### Signs and Symptoms - Polyuria with urine output of 5 to 15 L daily. - Polydipsia, especially a desire for cold fluids. - Marked dehydration, as evidenced by dry mucous membranes, dry skin, and weight loss. - Anorexia and epigastric fullness. - Nocturia and related fatigue from interrupted sleep. ### Diagnostic Test Results - High serum osmolality, usually above 300 mOsm/kg of water. - Low urine osmolarity, usually 50 to 200 mOsm/kg of water. - Low urine-specific gravity, less than 1.005. - Increased creatinine and blood urea nitrogen (BUN) levels resulting from dehydration. - Positive response to a water deprivation test: Urine output decreases and specific gravity increases. ### Management - The objectives of therapy are: - To replace ADH (usually a long-term therapeutic program) - To ensure adequate fluid replacement - To identify and correct the underlying cause. - **Treatments:** - Replacement of vasopressin therapy with intranasal or I.V. DDAVP (desmopressin acetate). - Correction of dehydration and electrolyte imbalances. - A thiazide diuretic to deplete sodium and increase renal water reabsorption. - Restriction of salt and protein intake. ## SIADH - Syndrome of Inappropriate Antidiuretic Hormone - SIADH is a disorder of impaired water excretion caused by the inability to suppress secretion or due to excessive secretion and action of Antidiuretic hormone. - If water intake exceeds the reduced urine output (concentrated urine), the ensuing water retention leads to the development of hyponatremia. - The most common cause of HYPOOSMOLAR EUVOLEMIC Hyponatremia. ### Etiology - **Neoplasms** - Carcinomas of - Lung - Duodenum - Pancreas - Ovary - Bladder, ureter - Other neoplasms - Thymoma - Mesothelioma - Bronchial adenoma - Carcinoid - Gangliocytoma - Ewing's sarcoma - **Head trauma (closed and penetrating)** - **Infections** - Pneumonia, bacterial or viral - Abscess, lung or brain - Cavitation (aspergillosis) - Tuberculosis, lung or brain - Meningitis, bacterial or viral - Encephalitis - AIDS - **Vascular** - Cerebrovascular occlusions, hemorrhage - Cavernous sinus thrombosis - **Genetic** - X-linked recessive (V2 receptor gene) - **Drugs** - Vasopressin or desmopressin - Chlorpropamide - Oxytocin, high dose - Vincristine - Carbamazepine - Nicotine - Phenothiazines - Cyclophosphamide - Tricyclic antidepressants - Monoamine oxidase inhibitors - Serotonin reuptake inhibitors - **Congenital malformations** - Agenesis corpus callosum - Cleft lip/palate - Other midline defects - **Neurologic** - Guillain-Barré syndrome - Multiple sclerosis - Delirium tremens - Amyotrophic lateral sclerosis - Hydrocephalus - Psychosis - Peripheral neuropathy ### Investigations Sent for Diagnosis of SIADH - Serum Na+, potassium, chloride, and bicarbonate. - Plasma osmolality. - Urine Sodium. - Urine osmolality. - Serum creatinine. - Blood urea nitrogen. - Blood glucose. - Serum uric acid. - Serum cortisol. - Thyroid-stimulating hormone. ### Management - **Fluid restriction** is a mainstay of therapy in most patients with SIADH, with a suggested goal intake of less than 800 mL/day. - The associated negative water balance initially raises the Serum sodium concentration towards normal and, with maintenance therapy in chronic SIADH, prevents a further reduction in serum sodium. - **Intravenous saline** is used for severe, symptomatic or resistant hyponatremia in patients with SIADH. This often requires the administration of sodium chloride. - If the serum sodium concentration is to be elevated, the electrolyte concentration of the fluid given must exceed the electrolyte concentration of the urine, not simply that of the plasma.