Pituitary Adenomas, Acromegaly, Gigantism, Dwarfism

GH, ACTH, TSH, FSH/LH, Prolactin

Name the hormones that the anterior pituitary gland releases

ADH, Oxytocin

Name the hormones that the posterior pituitary gland releases

tumor, hyperplasia, infarction, genetic disorders, trauma

Major causes of pituitary gland disorders

gigantism, acromegaly

Increased levels of GH leads to

dwarfism, lethargy, premature aging

Decreased levels of GH results in

Addisons disease

Decreased levels of ACTH results in

Cushing disease

Increased levels of ACTH results in

hyperthyroidism

Increased levels of TSH results in

hypothyroidism

Decreased levels of TSH results in

ammorrhea

Increased levels of prolactin results in

decreased milk production

Decreased levels of prolactin results in

precipitates childbirth, excess milk

Increased oxytocin results in

prolonged childbirth, diminished milk

Decreased oxytocin results in

SIADH

Increased levels of ADH results in

diabetes inspidus

Decreased levels of ADH results in

lactrotroph (prolactin)

What is the most common pituitary adenoma?

Pituitary Adenoma

A benign tumor that is usually slow growing and arise from any type of cell of the anterior pituitary

increased secretion of hormones, could be silent, decrease secretion of hormone due to compression

What are some things that can occur with pituitary adenomas

Head MRI, serum prolactin, GH, IGF-1, 24 hr urine free cortisol, ACTH, LH, FSH, T4, TSH

Patient presents to the clinic for amenorrhea which she states has been going on for about a year. She also reports that recently she has loss her peripheral vision in the last couple weeks as well as frequent headaches. What do you want to order?

endoscopic transphenoidal hypophysectomy, serial hormonal testing

Treatment plan for large, active pituitary adenomas

dopamine agonist (cabergoline), bromocriptine (not as good)

Phase 1 treatment plan for lactotroph

observation (mass, vision, hormone levels)

Game plan for <20 mm incidentalomas

Serial Serum prolactin, No further testing (2-4 mm), annual MRI (5-9 mm)

Game plan for <10 mm incidentalomas if asymptomatic

Empty sella syndrome

Enlarged sella turcica that is not entirely filled with pituitary tissue because it is flattened or shrunken and patient tends to be asymptomatic

Acromegaly

An excessive secretion of growth hormone (usually due to a pituitary somatotroph) AFTER epiphyseal closure that has an insidious onset with slow progression

Serum IGF-1

A 39 y/o male presents to the clinic for repeated HA and visual changes. Patient reports a PMHx of HTN, OSA, type 2 DM, and back pain. On physical exam you note an enlarged jaw, swollen hands and feet, coarse/acral facial features and a very deep voice. What lab do you want initally?

Oral glucose tolerance test with GH

A 39 y/o male presents to the clinic for repeated HA and visual changes. Patient reports a PMHx of HTN, OSA, type 2 DM, and back pain. On physical exam you note an enlarged jaw, swollen hands and feet, coarse/acral facial features and a very deep voice. IGF-1 came back iffy, what should you order next?

pituitary MRI

A 39 y/o male presents to the clinic for repeated HA and visual changes. Patient reports a PMHx of HTN, OSA, type 2 DM, and back pain. On physical exam you note an enlarged jaw, swollen hands and feet, coarse/acral facial features and a very deep voice. IGF-1 came back iffy, OGTT with GH levels showed inadequate suppression. What is your next step?

Look for ectopic source of GH

A 39 y/o male presents to the clinic for repeated HA and visual changes. Patient reports a PMHx of HTN, OSA, type 2 DM, and back painOn physical exam you note an enlarged jaw, swollen hands and feet, coarse/acral facial features and a very deep voice. IGF-1 came back iffy, OGTT with GH levels should inadequate suppression. Pituitary MRI is normal. Next step?

endoscopic transphenoidal surgery, Somatostatin analog, Cabergoline, competitive GH receptor agonist, radiation therapy

A 39 y/o male presents to the clinic for repeated HA and visual changes. Patient reports a PMHx of HTN, OSA, type 2 DM, and back painOn physical exam you note an enlarged jaw, swollen hands and feet, coarse/acral facial features and a very deep voice. IGF-1 came back iffy, OGTT with GH levels should inadequate suppression. Pituitary MRI is shows a mass. What is your treatment plan?

get the IGF-1 and GH concentrations to normal ranges, control adenoma size

Treatment goals for acromegaly

Gigantism

An excessive secretion of growth hormone that occurs BEFORE the fusion of the epiphyseal growth plates in a child/adolescent and results in a height 3 or 4+ SD

IGF-1, OGTT with GH, pituitary MRI

15 y/o girl presents to the clinic for a regular check up. On a physical exam you large hands and feet, coarse facial features, excessive sweating, an enlarged head. Mother notes that the child has yet to start her periods. Which labs/imaging do you want?

endoscopic tranphenoidal surgery, Bromocriptine (dopamine analong), octreotide (somatostatin analog), pegvisomant (competitive GH receptor antiagonist), radiation therapy (last resort)

Treatment plan for gigantism

Dwarfism

A growth hormone deficiency results in

xrays for bone age, Serum IGF-1, growth hormone provocation

Diagnostics for dwarfism

Recombinant GH (as young as possible), therapeutic monitoring every 4-6 months (height velocity, IGF-1, bone age)

Treatment plan for dwarfism