AssessmentsHypopituitarism: Pathology review
USMLE® Step 1 style questions USMLE
A 38-year-old woman comes to the emergency department because of a severe headache and multiple episodes of non-bloody, non-bilious emesis for the past few hours. Review of systems is significant for fatigue, constipation, and problems with peripheral field vision for the past few months. Her last menstrual period was 4 months ago. Temperature is 37.0°C (98.6°F), pulse is 58/min, respirations are 10/min, and blood pressure is 92/64 mm Hg. Physical examination shows a lethargic female complaining of severe pain. Visual field is tunneled with doubling of vision. Head magnetic resonance imaging is shown below:
Reproduced from: Wikimedia Commons
Which of the following is the most likely diagnosis?
Content Reviewers:Yifan Xiao, MD
On your rounds, you admit 28-year-old Regina who presents with an 8-month history of depression, cold intolerance, fatigue, and reduced libido.
History revealed she delivered a healthy baby eight months ago, and that the delivery was complicated by a severe postpartum hemorrhage.
Then you see Alexander, a 58-year-old male with difficulty seeing things in his peripheral vision. He also describes a loss of sex drive, erectile dysfunction, and significant weight gain, all starting approximately two years ago.
Basal serum hormone measurements were performed, showing decreased T4 levels in Regina and decreased FSH, LH, and testosterone levels in Alexander.
Hypopituitarism typically occurs because of an acquired or congenital issue where the hypothalamus or pituitary is injured. Now, the clinical picture of hypopituitarism depends on which hormone is missing.
Next, TSH deficiency presents with symptoms of hypothyroidism, like fatigue, cold intolerance, depression, bradycardia, decreased appetite, and constipation, as well as dry skin and a puffy face and slow relaxing reflexes.
Third, growth hormone deficiency is more obvious in children who present with short stature and failure to thrive - meaning, low height and weight for their age.
In adults, it can cause a decrease in bone mineral density and muscle mass, and an increase in fat content.
Diagnosis is based on suggestive symptoms and basal serum hormone measurements; however, dynamic testing may also be required in some cases.
If results are inconclusive, an ACTH-stimulation test with Cosyntropin, a synthetic analog of ACTH, is required.
That’s because although daily growth hormone secretion is pulsatile, it stimulates the liver to release a constant amount of IGF-1 throughout the day which can be used as an indicator for GH secretion.
Low serum IGF-1 levels indicate a growth hormone deficiency. However, this needs to be confirmed by using the arginine-L-Dopa combination test, where growth hormone levels are measured before and after giving an arginine hydrochloride infusion and oral levo-dopamine.
Low FSH, LH, or estradiol levels, as well as not bleeding following medroxyprogesterone, signify gonadotropin insufficiency.
In males, gonadotropin insufficiency diagnosis is based on low serum testosterone, FSH, and LH levels.
And fifth, serum prolactin levels are typically not measured because what’s considered a normal level, can vary from person to person.
Gonadotropin insufficiency is treated with testosterone in males, and combined estrogen and progestin therapy for females to replace the missing sex hormones. Finally, at the moment, there are currently no treatments available for prolactin deficiency.
Ok, so there are a few causes of hypopituitarism to know. The first high-yield cause is Sheehan syndrome, which is hypopituitarism secondary to ischemic pituitary necrosis due to severe postpartum bleeding, often this causes a decrease in all hormones.
Diagnosis is clinical, based entirely on history of pregnancy and birth and symptoms like galactorrea.
Treatment consists of lifelong hormone substitution therapy for each individual hormone that’s missing.
The syndrome can occur as a primary disorder, where the cause of the atrophy is unknown but it’s commonly associated with obese women.
Some high-yield secondary causes include pituitary surgery, head trauma, and idiopathic intracranial hypertension, previously known as pseudotumor cerebri, which is increased intracranial pressure without a detectable cause.
Now, most individuals are asymptomatic because pituitary function is typically normal. Others can develop hypopituitarism, headaches, high blood pressure, and, rarely, increased intracranial pressure, cerebrospinal fluid leakage through the nose, or cerebrospinal rhinorrhea, and vision abnormalities.
Full basal serum hormone measurements might also be required. No specific therapy is needed for an empty sella alone, but hormonal replacement might be needed.
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
- "Greenspan's Basic and Clinical Endocrinology, Tenth Edition" McGraw-Hill Education / Medical (2017)
- "Addison's disease and ACTH-producing pituitary microadenoma" Revista Médica Del Hospital General De México (2015)
- "Pituitary tumors: pathophysiology, clinical manifestations and management." Endocrine-related cancer (2001)
- "Diagnosis and Treatment of Hypopituitarism" BMJ (1954)