Differential Diagnosis for ACTH Deficiency
Single Most Likely Diagnosis
- Hypopituitarism: This is the most common cause of ACTH deficiency, often resulting from pituitary tumors, surgery, radiation, or other forms of pituitary damage. The pituitary gland's decreased ability to produce ACTH leads to a reduction in cortisol production by the adrenal glands.
Other Likely Diagnoses
- Adrenal Insufficiency (Secondary): This condition occurs when the adrenal glands do not receive enough ACTH from the pituitary gland, leading to decreased cortisol production. It can be caused by factors similar to those causing hypopituitarism.
- Pituitary Apoplexy: A medical emergency where a pituitary tumor suddenly hemorrhages or infarcts, leading to acute ACTH deficiency among other hormonal deficiencies.
- Lymphocytic Hypophysitis: An autoimmune condition that causes inflammation of the pituitary gland, potentially leading to ACTH deficiency.
Do Not Miss Diagnoses
- Sheehan Syndrome: A condition that occurs in postpartum women, characterized by necrosis of the pituitary gland, often due to severe blood loss during childbirth. It can lead to ACTH deficiency and is critical to diagnose due to its potential for severe morbidity and mortality if left untreated.
- Cranial Irradiation: Previous radiation therapy to the brain can lead to ACTH deficiency years after the treatment, making it a crucial diagnosis not to miss in patients with a history of cranial irradiation.
Rare Diagnoses
- Familial Isolated ACTH Deficiency: A rare genetic disorder that affects the production of ACTH, leading to adrenal insufficiency.
- Triple A Syndrome (Allgrove Syndrome): A rare autosomal recessive disorder characterized by adrenal insufficiency (including ACTH deficiency), alacrima (absence of tear secretion), and achalasia (swallowing difficulty).
- Prop1 Gene Mutation: A rare genetic mutation affecting the development of the pituitary gland, potentially leading to combined pituitary hormone deficiency, including ACTH deficiency.