Panhypopituitarism

By: Isra

Causes

• Pituitary adenoma (nonfunctional)
• Post surgery
• Infiltration by TB, sarcoidosis, haemochromatosis and histiocytosis X
• Pituitary infarction (Sheehan syndrome)
• Pituitary apoplexy (haemorrhage)
• Empty Sella turcica

Clinical features of the disease

• Low GH before puberty will lead to short stature, after puberty will lead to fatigue
• Low gonadotrophin before puberty will lead to delay puberty and after it will lead to amenorrhea, breast atrophy and infertility in female, in males it will leads to testicular atrophy, loss of libido and gynecomastia
• Low TSH will lead to hypothyroidism
• Low ACTH will lead to hyponatremia, alabaster skin, hypoglycemia and hypotension
• Hypopituitarism should be differentiated from polyglandular failure (Schidmet and carpenter syndrome) since they have hypoadrenalism, hypothyroidism and Type 1 diabetes.
• In hypopituitarism there is weight loss, low glucose level and reduce pigmentation and vice versa in PGF

Investigations

• Blood tests
  • A. Pituitary hormones
  • B. Baseline hypoglycemic test (insulin increase secretion of GH and ACTH) if no increase in these hormones in response to hypoglycemia it is considered positive i.e., diagnostic
  • C. Target hormones (estrogen, T4 and T3, Cortisol)
  • D. Blood potassium usually normal due to functioning RAAS
  • E. Iron profile
• Imaging
  • A. MRI pituitary
  • B. CT chest and abdomen to look for TB and sarcoidosis

Treatment

Treatment is mainly by replacement of the target hormones

1. Cortisone + compression stocking
2. Thyroxine
3. Sex hormones or gonadotrophins if fertility is required
4. Desmopressin if patient developed craniogenic diabetes insipidus
5. GH only if the patient has intractable fatigue despite appropriate dose of cortisol and thyroxine