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Anterior pituitary: endocinology, hypopituitarism apoplexy etc..

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A major organ of the endocrine system, the anterior pituitary (also called the adenohypophysis or pars anterior), is the glandular, anterior lobe that together with the posterior lobe (posterior pituitary, or the neurohypophysis) makes up the pituitary gland (hypophysis). The anterior pituitary regulates several physiological processes including stress, growth, reproduction and lactation. Proper functioning of the anterior pituitary and of the organs it regulates can often be ascertained via blood tests that measure hormone levels.

The anterior pituitary contains five types of endocrine cell, and they are defined by the hormones they secrete: somatotropes (GH); prolactins (PRL); gonadotropes (LH and FSH); corticotropes (ACTH) and thyrotropes (TSH)

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Anterior pituitary: endocinology, hypopituitarism apoplexy etc..

  1. 1. CLINICAL ENDOCRINOLOGY : ANTERIOR PITUITARY M C VASIF MAYAN
  2. 2. Pituitary disorders • 1. MASS – SECRETORY/ FUNCTIONING and COMPRESSIVE • 2. GRANULOMAS • 3. INFLAMMATORY ( HYPOPHYSITIS) • 4. VASCULAR
  3. 3. • MASS Adenoma • Tumours MEN-1, Mc Cune Albright, Carney syndrome • Other Parasellar Rathke cyst,granular cell tumour, chordoma, craniopharyngioma, meningioma, glioma, hematological malignancy • Granuloma Sarcoidosis Hand Schullen Christian disease Mets • Hypophysitis Lymphocytic/ Granulomatous/ Xanthomatous • Vascular Apoplexy/ Postpartum ( hemorrhage/ infarction)
  4. 4. Endocrinedisease Hormone excess Hormone deficiency Hormone resistance
  5. 5. Pituitary Gland • Located within the sella tursica • Weight 600mg • Contiguous to vascular and neurologic structures • Cavernous sinuses • Cranial nerves • Optic chiasma • Hypothalamic neural cells synthesize specific releasing and inhibiting hormones • Secreted directly into the portal vessels of the pituitary stalk • Blood supply derived from the superior and inferior hypophyseal arteries
  6. 6. Hypothalamic–Pituitary Axis
  7. 7. Pituitary Gland • Anterior pituitary gland • Secrete various trophic hormones • Disease in this region may result in syndromes of hormone excess or deficiency • Posterior pituitary gland • More of a terminus of axons of neurons in the supraoptic and paraventricular nuclei of the hypothalamus • Storehouse for the hormones • The main consequence of disease in this area is disordered water homeostasis
  8. 8. Anterior Pituitary Gland • Anterior Pituitary “Master gland” • Major blood source: hypothalamic-pituitary portal plexus • Allows transmission of hypothalamic peptide pulses without significant systemic dilution • Consequently, pituitary cells are exposed to sharp spikes of releasing factors and in turn release their hormones as discrete pulses. • Production of six major hormones: • Prolactin (PRL) • Growth hormone (GH) • Adrenocorticotropin hormone (ACTH) • Luteinizing hormone (LH) • Follicle-stimulating hormone (FSH) • Thyroid-stimulating hormone (TSH)
  9. 9. Anterior Pituitary Gland • Anterior Pituitary “Master gland” • Secreted in a pulsatile manner • Elicits specific responses in peripheral target tissues • Feedback control at the level of the hypothalamus and pituitary to modulate pituitary function exerted by the hormonal products of the peripheral target glands • Tumors cause characteristic hormone excess syndromes • Hormone deficiency • may be inherited or acquired
  10. 10. HORMONE DEFICIENCY • GONADOTROPIN DEFICIENCY • ACTH DEIFICIENCY • TSH DEFICIENCY • PROLACTIN DEFICIENCY • GROWTH HORMONE DEFICIENCY • HYPOPITUITARISM
  11. 11. Adult Growth Hormone Deficiency • First hormone to be affected • Non functioning adenoma/ irradiation • GH  FSH/LH  TSH  ACTH • • Adults • Often asymptomatic • Fatigue • Decreased exercise tolerance • Abdominal obesity • Loss of muscle mass • Abnormal lipid profile • Reduced BMD • Atherosclerosis , LV dysfunction, increased fibrinogen
  12. 12. Treatment : GH replacement 0.1 – 0.3 mg/day Maximum upto 1.25 mg/day Women need higher doses than men
  13. 13. Gonadotropin Deficiency Women • Oligomenorrhea or amenorrhea • Loss of libido • Vaginal dryness or dyspareunia • Loss of secondary sex characteristics (estrogen deficiency) Men • Loss of libido • Erectile dysfunction • Infertility • Loss of secondary sex characteristics (testosterone deficiency) • Atrophy of the testes • Gynecomastia (testosterone deficiency) Most common presenting feature of adult hypopituitarism
  14. 14. TSH Deficiency • Hypothyroidism • Atrophic thyroid gland
  15. 15. ACTH Deficiency • Most commonly due to glucocorticoid withdrawal • Results in hypocortisolism • Malaise • Anorexia • Weight-loss • Gastrointestinal disturbances • Hyponatremia, hypoglycemia • Pale complexion • No features of mineralocorticoid deficiency • Aldosterone secretion unaffected
  16. 16. Prolactin Deficiency • Inability to lactate postpartum • Often 1st manifestation of Sheehan syndrome
  17. 17. HYPOPITUITARISM Etiology • Anterior pituitary diseases • Deficiency one or more or all anterior pituitary hormones
  18. 18. hypopituitarism Developmenta / structural traumatic Neoplastic Infiltrative / inflammatory Vascular infections
  19. 19. developmental Transcription factor defect Aplasia / dysplasia Congenital mass / encephalocele Primary empty sella Congenital disorders
  20. 20. Hypopituitarism: Developmental and Genetic causes •Septo-Optic dysplasia •Prader Willi syndrome •Kallman Syndrome •Laurence-Moon-Biedl Syndrome •Frohlich Syndrome (Adiposo Genital Dystrophy)
  21. 21. • Septo-Optic dysplasia • Hypothalamic dysfunction and hypopituitarism • may result from dysgenesis of the septum pellucidum or corpus callosum • Affected children have mutations in the HESX1 gene • involved in early development of the ventral prosencephalon • These children exhibit variable combinations of: • cleft palate • syndactyly • ear deformities • hypertelorism • optic atrophy • micropenis • anosmia • Pituitary dysfunction • Diabetes insipidus • GH deficiency and short stature • Occasionally TSH deficiency
  22. 22. •Kallman Syndrome • Defective hypothalamic gonadotropin-releasing hormone (GnRH) synthesis • Associated with anosmia or hyposmia due to olfactory bulb agenesis or hypoplasia • May also be associated with: color blindness, optic atrophy, nerve deafness, cleft palate, renal abnormalities, cryptorchidism, and neurologic abnormalities such as mirror movements • GnRH deficiency prevents progression through puberty • characterized by • low LH and FSH levels • low concentrations of sex steroids
  23. 23. •Laurence-Moon-Biedl Syndrome • Rare autosomal recessive disorder •Characterized by mental retardation; obesity; and hexadactyly, brachydactyly, or syndactyly • Central diabetes insipidus may or may not be associated •GnRH deficiency occurs in 75% of males and half of affected females • Retinal degeneration begins in early childhood • most patients are blind by age 30 •Renal abnormalities
  24. 24. Traumatic Surgical resection Radiation damage Head injuries
  25. 25. Neoplastic Adenoma Parasellar mass Rathke’s cyst Craniopharyngioma Hamartoma Mets Leukemia / lymphoma Meningioma
  26. 26. Infiltrative/Inflammatory Lymphocytic hypophysitis Hemochromatosis Sarcoidosis Histiocytosis X Granulomatous hypophysitis
  27. 27. •LYMPHOCYTIC HYPOPHYSITIS • Etiology • Presumed to be autoimmune • Clinical Presentation • Women, during postpartum period with hyperprolactinemia • Mass effect (sellar mass) • Deficiency of one or more anterior pituitary hormones • ACTH deficiency is the most common • Diagnosis • MRI - may be indistinguishable from pituitary adenoma • Elevated ESR + • Treatment • Corticosteroids • Hormone replacement
  28. 28. Vascular Apoplexy Pregnancy related (infarction with DM , Sheehans) Sickle cell disease Arteritis
  29. 29. Quick Quiz!!! • When should you suspect pituitary apoplexy?
  30. 30. •PITUITARY APOPLEXY • Hemorrhagic infarction of a pituitary adenoma/tumor • Considered a neurosurgical emergency • Presentation: • Variable onset of severe headache • Nausea and vomiting • Meningism • Vertigo • +/ - Visual defects • +/ - Altered consciousness • Symptoms may occur immediately or may develop over 1-2 days Meningism is the triad of nuchal rigidity (neck stiffness) photophobia (intolerance of bright light) headache
  31. 31. • Pituitary Apoplexy • Diabetes • Bleed into a pre existing adenoma • Patients on warfarin • Post partum ( sheehans) • Hypertension • Sickle cell anemia • Shock
  32. 32. apoplexy • Severe hypoglycemia • Hypotension • Shock • CNS hemorrhage
  33. 33. Apoplexy •Usually resolve completely if treated correctly and early •Diagnose with CT/MRI •Differentiate from leaking aneurysm •Treatment: •Medical therapy – if symptoms are mild • Corticosteroids – high dose glucocorticoids • Surgical – Trans sphenoid decompression • Visual defects and altered consciousness
  34. 34. Infections Fungal (Histoplasmosis) Parasitic (Toxoplasmosis) Tuberculosis* Pneumocystis carinii
  35. 35. Hypopituitarism Diagnosis • Biochemical diagnosis of pituitary insufficiency • Demonstrating low levels of trophic hormones in the setting of low target hormone levels • Provocative tests may be required to assess pituitary reserve
  36. 36. Hypopituitarism Treatment • Hormone replacement therapy • usually free of complications
  37. 37. Hormone Replacement Trophic Hormone Deficit Hormone Replacement ACTH Hydrocortisone (10-20 mg A.M.; 10 mg P.M.) Cortisone acetate (25 mg A.M.; 12.5 mg P.M.) Prednisone (5 mg A.M.; 2.5 mg P.M.) TSH L-Thyroxine (0.075-0.15 mg daily) FSH/LH Males Testosterone enanthate (200 mg IM every 2 wks) Testosterone skin patch (5 mg/d) Females Conjugated estrogen (0.65-1.25 mg qd for 25days) Progesterone (5-10 mg qd) on days 16-25 For fertility: Menopausal gonadotropins, human chorionic gonadotropins GH Adults: Somatotropin (0.3-1.0 mg SC qd) Children: Somatotropin [0.02-0.05 (mg/kg per day)] Vasopressin Intranasal desmopressin (5-20 ug twice daily) Oral 300-600 ug qd
  38. 38. Take home points: • Remember that the cause may be functional • Treatment should be aimed at the underlying cause • Not all KKK are hypopituitarism • Hypopituitarism may present • Acutely with cortisol deficiency • After withdrawal of prolonged glucocorticoid therapy that has caused suppression of the HPA axis • Post surgical procedure • TUBERCULOSIS • DIABETES • SYSTEMIC HYPERTENSION • Post trauma • Hemorrhage
  39. 39. Pituitary Tumors
  40. 40. Pituitary Tumors •Microadenoma < 1 cm •Macroadenoma > 1 cm •Is the tumor causing local mass effect? •Is hypopituitarism present? •Is there evidence of hormone excess?
  41. 41. • Clinical presentation: • Mass effect • Superior extension • May compromise optic pathways – leading to impaired visual acuity and visual field defects • May produce hypothalamic syndrome – disturbed thirst, satiety, sleep, and temperature regulation • Lateral extension • May compress cranial nerves III, IV, V, and VI – leaning to diplopia • Inferior extension • May lead to cerebrospinal fluid rhinorrhea
  42. 42. Pituitary Tumors • Diagnosis • Check levels of all hormones produced • Check levels of target organ products • Treatment • Surgical excision, radiation, or medical therapy • Generally, first-line treatment surgical excision • Drug therapy available for some functional tumors • Simple observation • Option if the tumor is small, does not have local mass effect, and is nonfunctional • Not associated with clinical features that affect quality of life
  43. 43. Craniopharyngioma • Derived from Rathke's pouch. • Arise near the pituitary stalk • extension into the suprasellar cistern common • These tumors are often large, cystic, and locally invasive • Many are partially calcified • characteristic appearance on skull x-ray and CT images • Majority of patients present before 20yr • usually with signs of increased intracranial pressure, including headache, vomiting, papilledema, and hydrocephalus
  44. 44. Craniopharyngioma • Associated symptoms include: • visual field abnormalities, personality changes and cognitive deterioration, cranial nerve damage, sleep difficulties, and weight gain. • Children • growth failure associated with either hypothyroidism or growth hormone deficiency is the most common presentation • Adults • sexual dysfunction is the most common problem • erectile dysfunction • amenorrhea
  45. 45. Craniopharyngioma • Anterior pituitary dysfunction and diabetes insipidus are common • Treatment • Transcranial or transsphenoidal surgical resection • followed by postoperative radiation of residual tumor • This approach can result in long-term survival and ultimate cure • most patients require lifelong pituitary hormone replacement. • If the pituitary stalk is uninvolved and can be preserved at the time of surgery • Incidence of subsequent anterior pituitary dysfunction is significantly diminished.
  46. 46. Prolactinoma • Most common functional pituitary tumor • Usually a microadenoma • Can be a space occupying macroadenoma – often with visual field defects • Although many women with hyperprolactinemia will have galactorrhea and/ or amenorrhea • The absence these the two signs do not excluded the diagnosis • GnRH release is decreased in direct response to elevated prolactin, leading to decreased production of LH and FSH
  47. 47. Prolactinoma • Women • Amenorrhea – this symptom causes women to present earlier • Infertility • Galactorrhea • Men • Impotence – often ignored • Tend to present later • Signs of mass effect
  48. 48. Hyperprolactinemia • Essential to rule out secondary causes!! • Drugs – basically all anti dopaminergic drugs • Atypical antipsychotic – risperidone • METOCLOPRAMIDE • AMITRYPTILINE • Alpha METHYL DOPA • CCB – Verapamil • Estrogen • H2 antagonists - RANITIDINE • Hypothyroidism • CKD • Cirrhosis • Epileptic Seizures
  49. 49. •If prolactin level > 200mcg/L, almost always a prolactinoma (even in a nursing mother) •Prolactin levels correlate with tumor size in the macroadenomas •Suspect another tumor if prolactin low with a large tumor
  50. 50. Prolactinoma •Diagnosis •Assess hypersecretion • Basal, fasting morning PRL levels (normally <20 ug/L) •Multiple measurements may be necessary • Pulsatile hormone secretion • levels vary widely in some individuals with hyperprolactinemia •Hypothyroidism should be excluded by measuring TSH and T4 levels
  51. 51. Prolactinoma •Treatment •Medical • Cabergoline – dopamine receptor agonist • Bromocriptine - dopamine agonist • Safe in pregnancy • Will restore menstruation • Decreases both prolactin and tumor size (80%) •Surgical • Transsphenoidal surgery • Irradiation
  52. 52. Quick Quiz!!! • What type of tumors are most prolactinomas? • Prolactin levels >200 almost always indicate what? • Do prolactin levels correlate with tumor size?
  53. 53. Answer • What type of tumors are most prolactinomas? Microadenomas • Prolactin levels >200 almost always indicate what? Almost always indicates prolactinoma • Do prolactin levels correlate with tumor size? Yes, in macroadenomas
  54. 54. Growth Hormone Tumors • Gigantism • GH excess before closure of epipheseal growth plates of long bones • Acromegaly • GH excess after closure of epipheseal growth plates of long bones • Insidious onset • Usually diagnosed late
  55. 55. Growth Hormone Tumors • May have DM or glucose intolerance • Hypogonadism • Large hands and feet • Large head with a lowering brow and coarsening features • Hypertensive – 25% • Colon polyps • 3-6 more likely than general population • Multiple skin tags
  56. 56. Growth Hormone Tumors • Diagnosis • Screen: • Check for high IGF-I levels (>3 U/ml) • Remember, levels very high during puberty • Confirm: • 100gm glucose load • Positive: GH levels do not increase to <5ng/ml • Treatment • Surgical • Radiation • Bromocriptine - temporary measure • May decrease GH by 50% • Octreotide • For suboptimal response to other treatment
  57. 57. Quick Quiz!!! • How do you screen for acromegaly?
  58. 58. Answer • Check for high IGF-I levels (>3 U/ml)
  59. 59. Case 1 • 80-year-old man with history of hypertension (requiring three antihypertensive agents) and type 2 diabetes mellitus (managed with two oral hypoglycaemic drugs) was admitted with a fractured neck of femur following a low-trauma fall. • He was admitted to the orthopaedic ward to await fixation. • However, he became hypotensive and required ionotropic support and fluid resuscitation. • His haemoglobin decreased (12.5 to 9.3 g/dl) and acute renal dysfunction developed. The blood glucose was well controlled.
  60. 60. • Four days after admission the patient was considered fit for hemiarthroplasty. Immediately postoperatively he became hypoglycaemic and progressively drowsy, with no FND including visual fields. Hyponatraemia and hypotension occurred. • Full thyroid function testing showed hypothyroidism • free T3 1.9 [3.4–5.6 pmol/L] • free T4 6.4 [9–20 pmol/L] • TSH 1.0 mU/L [0.3–5.5] • Whats the diagnosis?
  61. 61. Case 2 • A previously healthy 64-year-old woman presented to the emergency room with a three-day history of feeling generally unwell, drowsiness and acute onset, severe headache. • She had a decreased level of consciousness and a temperature of 39°C. No ophthalmoplegia, visual field defect or other focal neurological signs were present. She had a leucocytosis and raised C-reactive protein (CRP) with normal serum sodium. The chest radiograph was unremarkable and computed tomography (CT) of the brain was reported as showing involutional changes. • Cerebrospinal fluid demonstrated • 220 red cells per µL • 408 white cells per µL (83% polymorphs, 17% lymphocytes) • Proteins 1.7 g/L (NR 0.1–0.4) • glucose 40 mg/dl
  62. 62. • The patient was presumed to have pneumococcal meningitis • intravenous ceftriaxone was administered. • No response • Culture of CSF negative • Hormone tests revealed panhypopituitarism
  63. 63. MRI brain showing a haemorrhagic lesion of the pituitary gland extending to the optic chiasm causing displacement of the optic nerve, consistent with pituitary macroadenoma
  64. 64. Diagnosis: pituitary apoplexy related to haemorrhage with resultant hypopituitarism Hydrocortisone and thyroxine were commenced. Mass reduced at 3 years of follow up

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