What is hypophysitis?

From the Guidelines

Hypophysitis is inflammation of the pituitary gland, which can occur due to various causes, including autoimmune disorders, infections, medications, or as part of IgG4-related disease, and is characterized by symptoms resulting from hormonal imbalances, such as headaches, vision changes, fatigue, and hormonal deficiencies.

Definition and Causes

Hypophysitis is a condition that affects the pituitary gland, a small gland located at the base of the brain, and can be caused by various factors, including autoimmune disorders, infections, medications (particularly immune checkpoint inhibitors used in cancer treatment), or as part of IgG4-related disease 1.

Symptoms and Diagnosis

Symptoms of hypophysitis typically result from hormonal imbalances and may include headaches, vision changes, fatigue, nausea, low blood pressure, and various hormonal deficiencies such as hypothyroidism, adrenal insufficiency, or diabetes insipidus 1.

Treatment and Management

Treatment depends on the underlying cause but often involves hormone replacement therapy to address specific deficiencies, such as hydrocortisone for adrenal insufficiency, levothyroxine for hypothyroidism, or desmopressin for diabetes insipidus 1.

• Key considerations in management include:
  • Referral to endocrinology for education on steroid stress dosing, emergency injections, and a medical alert bracelet or necklace, accessory, or system 1.
  • Holding immune checkpoint inhibitors until the patient is stabilized on replacement hormones 1.
  • Initiating replacement therapy with hydrocortisone for adrenal insufficiency, and considering other hormone replacements as needed 1.
  • Titrating hydrocortisone to a maximum of 30 mg daily total dose for residual symptoms of adrenal insufficiency, and reducing maintenance dosing for symptoms of iatrogenic Cushing’s syndrome 1.

Long-term Management

The condition can be temporary or permanent, and long-term management often requires regular monitoring of hormone levels and adjustment of replacement therapies under endocrinologist supervision 1.

• Important aspects of long-term care include:
  • Education on stress dosing for sick days, use of emergency steroid injectables, and when to seek medical attention for impending adrenal crisis 1.
  • Consideration of the need to start corticosteroids first when planning hormone replacement therapy for multiple deficiencies to avoid adrenal crisis 1.
  • Awareness of the potential for isolated central adrenal insufficiency with a low ACTH in patients with a recent history of treatment with corticosteroids and no other central hormone deficiencies 1.

From the Research

Definition of Hypophysitis

• Hypophysitis is a heterogeneous condition that leads to inflammation of the sella and/or suprasellar region, potentially resulting in hormonal deficiencies and/or mass effects 2.
• It is a broad term used to describe conditions leading to inflammation of the pituitary gland and the pituitary stalk, which may develop as a primary condition or secondary to other diseases 3.
• Hypophysitis is characterized by inflammation of the pituitary gland that can be primary (PH) or secondary (SH) to other diseases or following drug administration 4.

Classification and Causes of Hypophysitis

• Hypophysitis can be classified using anatomical, histopathological, and aetiological criteria 5.
• The condition can be caused by autoimmune disorders, inflammation secondary to sellar tumors or cysts, systemic diseases, infection, or drug-induced causes 6.
• Lymphocytic hypophysitis (LH) is the commonest cause of primary hypophysitis, whereas IgG4-related hypophysitis is increasingly being recognized 4.

Clinical Presentation and Diagnosis of Hypophysitis

• The clinical presentation of hypophysitis varies from an asymptomatic condition to a fatal disease, often as a result of electrolyte abnormalities due to glucocorticoid deficiency in the context of adrenal crisis from central adrenal insufficiency 2.
• Patients with hypophysitis typically present with headaches, some degree of anterior and/or posterior pituitary dysfunction, and enlargement of the pituitary gland and/or stalk, as determined by imaging 6.
• Diagnosis can be challenging, and ultimately, only a pituitary biopsy can confirm hypophysitis type and rule out other etiologies 6.

Treatment and Management of Hypophysitis

• The basic therapy relies on hormonal replacement, and high doses of steroids are the first-line treatment of symptoms caused by mass effect in sella and compression of surrounding structures 3.
• In steroid-resistant patients or in cases of unacceptable side effects, treatment with other immunosuppressant drugs may be administered with success 3.
• Surgery may be necessary in some cases to relieve mass effect and allow a definite diagnosis 6.