Pituitary Lesions PDF

 The endocrine system widely distributed group of organs that control the metabolic equilibrium between the various organs of the body. Includes: 1. Pituitary gland. 2. Thyroid gland 3. Parathyroid gland. 4. Adrenal cortex. 5. Adrenal medulla. 6. Pineal gland. 7. Pancreas  Hypo func...

 The endocrine system widely distributed group of organs that control the metabolic equilibrium between the various organs of the body. Includes: 1. Pituitary gland. 2. Thyroid gland 3. Parathyroid gland. 4. Adrenal cortex. 5. Adrenal medulla. 6. Pineal gland. 7. Pancreas  Hypo function of an endocrine organ Destruction of an endocrine gland due to *Inflammation *Infection *Vascular causes: ischemic necrosis, infarction *Neoplastic growth. Because most endocrine glands have significant endocrine reserve, 75-90% of the gland must be destroyed before hypo function appears  Hyper function Tumors, particularly benign ones, can produce hyper function of endocrine organs. One example is an adenoma of the adrenal gland. The normal microscopic appearance of the pituitary gland is shown here. The adenohypophysis is at the right and the neurohypophysis is at the left.  Tumors of the anterior pituitary Pituitary Adenoma Pituitary adenocarcinoma Cranio-pharyngioma.  Pituitary Adenoma N/E: Capsulated, soft, brown mass compressing the surrounding tissue. C/P: (secretory or non secretory) Excess hormone production (acromegaly, gigantism, Cushing syndrome, hyerprolactinemia, hyperthyroidism, rarely gonatropin excess) Large tumors (>1 cm): mass effects (headache, visual disturbances, pressure on surrounding pituitary tissue which may later lead to hypopituitarism) Hemorrhagic necrosis in the gland (surgical emergency)  Pituitary adenocarcinoma Rare, may complicate Chromophobe adenoma. Destroys the base of sella turcica and extends to nasopharynx.  Craniopharyngioma Site: They are derived from epithelial remnants of Rathke's Pouch. Craniopharyngioma arises in children and young adults and is always benign.  Effects: 1Compression on the hypothalamus and pituitary gland (hypo-function and related hormone deffeciency). 2 Posterior pituitary Hypo-function. Diabetes insipidus due to deficient secretion of ADH hormone. Presents with polyuria and polydipsia 3 Headache (most common due to mass effect or hydrocephalus)  HYPERPITUITARY SYNDROMES Definition: Hyper function of the anterior pituitary gland Causes: due to either 1- Hyperplasia 2-Adenoma (common) 2- Carcinoma (rare). Effects: l. Hyperprolactinemia (increase prolactin) 2.Gigantism (before closure of the epiphysis) or acromegally (after closure of the epiphysis) (increase growth hormone). 3. Cushing syndrome (increase ACTH). 4- Hyperthyroidism C/P: The symptoms of hypopituitarism usually start slowly and get worse over time. But for some patients, symptoms start suddenly. Vary from person to person. Symptoms depend on type of hormone deficiency. Effects 1Pituitary dwarfism (Growth hormone (GH) deficiency) Failure to produce normal amounts of growth hormone in childhood can cause growth problems and short stature 2 Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) deficiency Leads to infertility 3 Thyroid-stimulating hormone (TSH) deficiency Leads to hypothyroidism. 4Adrenocorticotropic hormone (ACTH) deficiency 5- Anti-diuretic hormone (ADH) deficiency diabetes insipidus 6- Prolactin deficiency Decreased milk formation during lactation