What are the causes of panhypopituitarism?

Causes of panhypopituitarism

• Pituitary masses (Tumours, cysts)
• Extra-pituitary tumours (Craniopharyngioma) 
• Pituitary surgery 
• Pituitary irradiation 
• Sheehan syndrome (Infarction after massive haemorrhage, e.g. during childbirth)
• Pituitary apoplexy 
• Infiltrative disorders (Haemochromatosis, lymphocytic hypophysitis)
• Genetic disorders [Mutation in PROP-1 or POU1F1 (previously known as Pit- 1)]
• Hypothalamic disorders

Source:

• Kumar and Clark's clinical medicine, 9th Edition (Fig 26.7)
• Rapid review of clinical medicine for MRCP part 2, 2nd Edition, by Sanjay Sharma and Rashmi Kaushal; page 373

Additional:
Panhypopituitarism: Defective or absent function of the entire pituitary gland. AkA pituitary cachexia; AKA Simmonds disease. (AKA= Also Known As)