Isolated ACTH deficiency and primary hypothyroidism.

A patient presented with severe primary hypothyroidism and secondary adrenal insufficiency due to the isolated deficiency of ACTH. The diagnostic evidence suggests that both are of an autoimmune aetiology. Acquired isolated or unitrophic ACTH deficiency is a rare but definite cause of adrenal insufficiency. Additional case reports and autopsy studies describing acquired isolated ACTH deficiency associated with autoimmune thyroid disease have appeared in the literature suggesting that the association is more than coincidental. Combined thyroid and adrenal failure should not always be considered to be the result of combined end organ failure. Unitrophic isolated ACTH deficiency may coexist with primary hypothyroidism.