Pathophysiology

Deficiency of hypothalamic releasing hormones or of pituitary trophic hormones can be selective or multiple.

• Isolated deficiencies can be genetic, congenital, sporadic, autoimmune or idiopathic
• Multiple deficiencies usually result from tumour growth or other destructive lesions - usually progressive loss on anterior pituitary function
• Panhypopituitarism refers to deficiency of all anterior pituitary hormones; it is most commonly caused by pituitary tumours, surgery or radiotherapy.

Most common causes of hypopituitarism: tumours, surgical, radiotherapy

Particular syndromes related to hypopituitarism:

• Kallman’s syndrome
• Septo-optic dysplasia
• Sheehan’s syndrome
• Pituitary apoplexy - A pituitary tumour occasionally enlarges rapidly owing to infarction or haemorrhage
• ‘Empty sella’ syndrome

PC

Symptoms of a deficiency of a pituitary stimulating hormone are the same as those of primary deficiencies of the peripheral endocrine gland:

• hypothyroidism
• hypoadrenalism
• hypogonadism