Panhypopituitarism Flashcards
What are the hypothalamic causes of hypopituitarism?
Tumors
- Craniopharyngioma
- Metastasis from malignant tumors e.g. lung and breast CA
Infarct / Stroke (rare)
Radiation therapy
- Can lead to hypothalamic / pituitary dysfunction or both
Is dose and time-dependent, and may not become apparent until many years s/p treatment
- Hence impt for pt post-therapy to go for regular screening
Infiltrative lesions :
- Marked thickening of infundibulum on MRI is a common finding
- Conditions include Sarcoidosis and Langerhans cell histiocytosis
Infections: TB, Candida, Hanta virus
Traumatic brain injury (TBI)
What are the pituitary causes of hypopituitarism?
Mass lessions
- Most commonly by a non-secretory pituitary macroadenoma > 1cm
- Commonly: HG, Prolactinoma, Non-Secreting pituitary tumor
Pituitary surgery – Pituitary function may be better or worse afterwards
Pituitary radiation
Sheehan syndrome
Pituitary apoplexy
Snake bite: Russell viper bites have been shown to cause hemorrhagic necrosis of the pituitary
Hemochromatosis : Gonadotropin deficiency is the most common endocrine abnormality
How does non secretory pituitary adenoma present?
Presents with loss of multiple anterior pituitary hormone deficiencies
- GH and gonadotrophins are usually first affected
- TSH and ACTH are usually last to be affected
A/w HYPERPROLACTINAEMIA due to Stalk Compression Syndrome
- Loss of dopaminergic inhibition from hypothalamus
- Don’t confuse this w/ prolactinoma 🡪 will p/w macroadenoma w/ Prolactinaemia >4-5x ULN; whereas in SCS prolactin levels usually 2x ULN
What is Sheehan’s syndrome and how does it present?
Infarction after postpartum haemorrhage, often severe as to cause hypotension and require multiple transfusions
In severe hypopituitarism, patient may develop lethargy, anorexia, weight loss, and inability to lactate during the first days/weeks after delivery
In mild hypopituitarism, there may be delay in recognition for many year
What is pituitary apoplexy and how does it present?
Sudden haemorrhage into the pituitary gland, often into a pituitary adenoma
This may produce severe headache, double vision and sudden severe visual loss, sometimes followed by acute life-threatening hypopituitarism.
Often pituitary apoplexy can be managed conservatively with replacement of hormones and close monitoring of vision, although if there is a rapid deterioration in visual acuity and fields, surgical decompression of the optic chiasm may be necessary.
How does a patient with growth hormone deficiency present?
- Growth Failure (during childhood) -> Dwarfism
- ↓ bone density
- Muscle atrophy & weakness
How does a patient with prolactin deficiency present?
Lactation Failure following delivery
Asymptomatic in Males
How does a patient with central TSH deficiency present?
- Weight gain
- LOA
- Cold intolerance
- Lethargy
- Constipation
- Dry skin
- Menstrual Change (Oligo/Menorrhagia)
How does a patient with 2’ adrenal deficiency present?
- HypoNa
- HypoTN
- Hypoglycaemia
- Lethargy
- Hypoandrogenism (in women)
How does a patient with ADH deficiency present?
Central DI 🡪 polyuria, polydipsia
How does a patient with oxytocin deficiency present?
No Effect
How does a male with 2’ hypogonadism present?
- Testicular Atrophy
- Gynecomastia
Infertility, Loss of libido
Menopausal / Andropausal S&S, Osteoporosis, CV S/E
How does a female with 2’ hypogonadism present?
Amenorrhea
What is Kallman’s syndrome?
Isolated gonadotrophin (GnRH) deficiency due to mutations in the KAL1 gene on the short arm of X Ch
Characterized by anosmia
What is septo- optic dysplasia?
- Congenital syndrome associated with mutations in the HESX1 gene 🡪 resulting in developmental abnormality of the forebrain
- Presents in childhood with a clinical triad of midline forebrain abnormalities, optic nerve hypoplasia and hypopituitarism.
