PATH 1: Pathology of Pituitary, Hypothalamus & Adrenal Glands

Question 1

Most Common Tumor of the Hypothalamus?

Answer 1

Craniopharyngioma

Rathke Pouch Remnant: benign Tumor: Usually occurs near pituitary stalk

HIGH risk of morbidity: Endocrine and hypothalamic effects

Treated w/ surgery/Radiology => 90% survival at 10 year

Question 2

Pituitary (Sellar) Mass Effects?

Answer 2

Visual field Disturbances (depends on duration and extent of optic chiasm compression)

Nassau/Vomiting

Question 3

Causes of Hypopituitarism?

Answer 3

Pituitary tumor

Extra-Pituitary tumor (compresses adjacent pituitary tissue preventing function)

Ischemic:

• Sheehan’s Syndrome: Post-Partum Hemorrhage =>Acute infarction w/ necrosis of anterior pituitary lobe => Mild hypopituitarism =>Failure to Lactate
• Stroke/Hemorrhage
• Snake Bites

Traumatic Brain Injury

Inflammatory (Hypophytitis)

Genetic

Question 4

____________: Post-Partum Hemorrhage =>Acute infarction w/ necrosis of anterior pituitary lobe => Mild hypopituitarism =>Failure to Lactate

Answer 4

Sheehan’s Syndrome: Post-Partum Hemorrhage =>Acute infarction w/ necrosis of anterior pituitary lobe => Mild hypopituitarism =>Failure to Lactate

Question 5

Clinical Presentation of Hypopituitarism?

Anterior vs. Posterior?

Answer 5

ANTERIOR

• GH deficiency (dwarfism)
• LH/FSH deficiency (infertility, amenorrhea)
• ACTH deficiency (hyponatremia, hypotension)
• Prolactin deficiency (failure of lactation)
• Pallor (lack of MSH - Melancocyte Stimulating Hormone)

POSTERIOR: ADH Deficiency (Diabetes Insipidus)

Question 6

Causes of Hyperpituitarism?

Answer 6

• Pituitary Adenoma (Anterior Lobe) MOST COMMON CAUSE OF HYPERPITUITARISM => Prolactinoma most commonly
• Pituitary Carcinoma (RARE)
• Pituitary Hyperplasia
• Hypothalamic Disorders

Question 7

Commonest manifestation of Pituitary Adenoma?

Answer 7

HYPERPITUITARISM => Prolactinoma

Question 8

Anterior Pituitary Syndromes?

Answer 8

Somatotroph Adenoma (GH secreting) => ACROMEGALY

Lactotroph Adenoma (Prolactin secreting) => Primary cause of Amenorrhea

Question 9

Cause/Symptoms/Diagnosis of Acromegaly?

Answer 9

Cause: Somatotroph Adenoma (GH secreting tumor of Anterior Pituitary) => Excess GH => Acromegaly

Symptoms:

• Mass Effects (Visual Disturbances)
• Hormone Effects (Hypopituitarism)
• Metabolic Effects (Diabetes Insipidus, Hypertension)
• Soft Tissue Effects

Diagnosis

• IGF1
• Failure to suppress GH on glucose tolerance test
• MRI to localize adenoma

Question 10

Primary cause of Amenorrhea?

Treatment?

Answer 10

Lactotroph Adenoma (Anterior Pituitary)

Also Low libido, galactorrhea (Spontaneous milk excretion)

Treatment: Dopamine Agonist (Cabergoline)

Question 11

Posterior Pituitary Syndromes?

Answer 11

Diabetes Insipidus (ADH deficiency)=> Polyuria (excess urination)

Syndrome of Inappropriate ADH (SIADH) => Resorption of excess amounts of free water

Question 12

Symptoms/Causes of Diabetes Insipidus?

Answer 12

Diabetes Insipidus (ADH deficiency)

Symptoms: Polyuria (excess urination), thirst & polydipsia (excess drinking) due to increased serum sodium

Causes: Brain trauma, Tumors, Infection

Question 13

Symptoms/Causes of SIADH?

Answer 13

Syndrome of Inappropriate ADH (SIADH)

Symptoms: Resorption of excess amounts of free water=> Hyponatremia and Cerebral Edema

Causes: Ectopic ADH secretion (lung carcinoma), Drugs, Infection

Question 14

Functions of each part of the Adrenal Gland?

Answer 14

Adrenal Cortex:

• Salt: Glomerulosa - Mineralocorticoids (Aldosterone) regulate water/salt ballance
• Sugar: Fasciculata - Glucocorticoids (anti-inflammatory in all tissues, and control metabolism in muscle, fat, liver and bone)
• Sex: Reticularis - Adrenal Androgens (DHEA)

Adrenal Medulla:

• Neuroendocrine tissue (Chromaffin cells) - Produce Catecholamines (Epinephrine/Norepinephrine)

Question 15

Casues/Manifesations of Hypercortisolism (aka. _________________)

Answer 15

Hypercortisolism (Cushing’s Syndrome) caused by:

Exogenous (Steroids) MOST COMMON

Endogenous (ACTH -DEPENDENT)

• Pituitary adenoma => Cushing’s Disease
• Ectopic production by non-pituitary tumor (Lung)

Endogenous (ACTH- INDEPENDENT)

• Adrenal Tumours
• Hyperplasia (Uncommon)
• Elevated serum cortisol w/ Decreased ACTH

Question 16

Pathophysiology and Diagnosis of Hypercortisolism (Cushing’s Syndrome)?

Answer 16

1) Prove Cortisol excess via urine/serum testing

2) Attempt to suppress cortisol using DEXAMETHASONE

• Suppression= NO steroid excess OR cyclical secretion of cortisol

3) Measure ACTH

• Suppressed: ACTH Independent =>adrenal pathology likely
• Raised: Pituitary/Ectopic Tumor (LUNGS) => Excess ACTH

4) Image either Lungs or Adrenals depending on ACTH Status

Question 17

Causes/Manifestations of Hyperaldosteronism ( aka. _______________)?

Answer 17

Causes of Hyperaldosteronism ( aka. Conn’s Syndrome)?

Adenoma => Mineralocorticoid (Aldosterone) excess causing:

• Hypertension
• Unexplained Hypokalemia
• Metabolic Ankylosis

Question 18

Diagnosis/Treatment of Hyperaldosteronism (Primary/Secondary) (Conn’s Syndrome)?

Answer 18

Diagnosing:

Renin Activity

• PRIMARY Hyperaldosteronism (SUPPRESSED Renin)
• SECONDARY Hyperaldosteronism (ELEVATED Renin)

Aldosteronism Concentration

Salt loading (Aim is to supress aldosterone levels)

Adrenal Vein Sample (to rule out ectopic production)

Treatment:

• Surgical Excision if unilateral
• Corticosteroid if type 1 FHA
• Aldosterone antagonist (Spironolactone)

Question 19

Virilizing adrenal tumors, not Congenital Adrenal Hyperplasia (CAH) are assumed to be _________ !!

Prevalence of Adrenal Tunours?

Answer 19

Virilizing tumors not Congenital Adrenal Hyperplasia (CAH) are assumed to be malignant!!

Carcinoma» Adenoma>Hyperplasia

Question 20

Conditions caused by Hyperfunction of the Adrenal Gland?

Answer 20

Hypercortisolism (Cushing’s Syndrome)

Hyperaldosteronism (Primary/Secondary) (Conn’s Syndrome)

Adrenal Syndromes

Question 21

Tumours of the Adrena Cortex?

Answer 21

Question 22

Tumours of the Adrena Medula?

Answer 22

Neoplasms arise from neuroendocrine (Chromaffin) Cells

Phaeochromocytoma: Secretes catecholamines (Epinephrine/Norepinephrine)