Hypopituitarism Hormone deficiency caused by the inadequate secretion of one or more of the hormones normally secreted by the pituitary, is known as hypopituitarism. It may commonly be caused by compression of the normal pituitary tissue by an enarging pituitary tumour, by pituitary surgery, or Radiotherapy.
If hypopituitarism is caused by tumour compression, function may be partially or fully recovered after surgery or medical therapy to reduce the size of the tumour. Pituitary surgery may cause hypopituiatarism in a minority of cases and improve pituitary function in others, and can be transient (particularly Diabetes Insipidus). Detailed post-operative endocrine assessment is therefore essential. Hypopituitarism after treatment of a Pituitary tumour by radiotherapy typically develops slowly and progressively over a period of several years. Presenting symptomsSymptoms of Hormone Deficiency Symptoms | Deficient Hormone |
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| Growth retardation in children. Adults: excessive tiredness, muscle weakness, lack of drive, impaired quality of life scores | GH | | Hypogonadism - In men: reduced facial and body hair, low libido, impotence; in women: Amenorrhoea, reduced libido, dyspareunia and hot flushes | FSH/LH | | Weight gain, decreased energy, sensitivity to cold, constipation, dry skin | TSH | | Pale appearance, weight loss, low blood pressure, dizziness, tiredness, 'collapse' during interrcurrent illness | ACTH | | Thirst, polyuria and nocturia - diabetes insipidus | AVP |
Acute hypopituitarism (e.g., pituitary Apoplexy) - sudden headache, collapse, hypothermia, hypoglycaemia and hypotension - may be a life-threatening emergency. Prompt steriod replacement is required for ACTH deficiency presenting acutely and during intercurrent illness in established ACTH deficiency. InvestigationsTests for hypopituitarism should be performed under the guidance of an Endocrinologist. Please see 'Who and When to Refer' (factsheet 14). Growth hormone GH deficiency in children will require referral to a paediatric endocrine centre. Adult GH deficiency requires specialist assessment. Gonadal function FSH, LH, PRL, oestradiol and Testosterone are assessed by serum levels. If fertility is desired, then a different approach to hormone replacement will be needed and a full assessment of both partners will be carried out. Thyroid function In pituitary-dependent Hypothyroidism circulating thyroid hormone levels are low or low-normal but TSH can be low, normal or even slightly elevated. Laboratories must be asked for free Thyroxine as well as TSH, and thyroid hormone replacement adjusted on the basis of free thyroxine level. Adrenal function ACTH stimulated secretion of Cortisol is assessed using the short synacthen or the insulin stress test. Diabetes insipidus (factsheet 8) The diagnosis and cause is usually obvious but sometimes a water deprivation test is performed. Treatment possibilities (for full details see factsheet 11)
GH - Synthetic GH given to children. The treatment of adults with replacement GH is clinically effective for many (though not all) patients with GH deficiency. NICE has issued guidelines to identify patients in whom treatment is required.
ACTH - Treatment is usually with Hydrocortisone (=cortisol). Prednisolone or dexamethasone are occasionally used. Increased doses required during stress including intercurrent illness. TSH - Treatment with L-thyroxine. FSH/LH - Treatment with Oestrogen and progestogen in women. Testosterone replacement in men given intramuscularly (i.m. every 2-4 weeks), transdermally, orally, via buccal mucosa or by implant. for fertility, treatment with gonadotropins is required at a specialist centre which provides effective monitoring. The specialist centre should have high resolution ultrasonography available and the objective is a singleton pregnancy. AVP -Ttreatment with Desmopressin (DDAVP) by nasal insufflation or tablets. Patient managementManagement of patients with hypopituitarism on multiple hormone-replacement therapy will entail life-long supervision by an endocrine outpatient clinic. The time interval for specialist monitoring will vary with the patient and the treatment received, but will probably be at intervals of 2-6 months immediately post-treatment, to annual or biennial in the longer term. Patients may need help with managing hydrocortisone therapy (factsheet 11). WatchpointsUrgent - refer to hospital- Deterioration of vision
- Clear fluid dripping down the back of the throat or through the nose soon after surgery (CSF leak - factsheet 9)
- As emergency if unable to take increased oral steroid replacement during acute intercurrent illness (e.g., vomiting)
Non-urgent (but still very important)- If the patient is on hydrocortisone, ensure that replacement therapy is increased when seriously ill or under major physical or psychological stress
- Watch for gradual deterioration in endogenous pituitary function and provide replacement therapy as required
Questions patients may askWill I have to take tablets in the long term? If the pituitary tumour or treatment for it has affected the function of the normal pituitary, its function does not usually recover and will need to be replaced in the long term. This involves daily tablet treatment. Will I need regular check-ups? Yes, but pituitary tumours are usually well controlled and, if they regrow at all, grow very slowly. Outpatient appointments are usually made 12 months to 2 years apart. Will I need regular scans? Perhaps, but again, these too are carried out years apart. Will I still be able to have a family? Yes, if the reason for infertility is pituitary disease. The effects of pituitary tumours on fertility can be treated, although some treatments are not paid for by the NHS. See also factsheet 11. If I take replacement therapy, will I feel exactly the same as I did before my pituitary tumour developed? Every patient is different, and replacement therapy remains an inexact science when compared with the intricate balance achieved in normal health, but most patients adapt very well in time and live a full, normal life. Have I inherited this, will my children get it? In all but very exceptional circumstances there is no hereditary link. Resources for patientsPlease go to the Resource Library of this website to access resources for patients. Our library includes literuature, newsletters and articles available from The Pituitary Foundation as well as the contact information for other organisations who provide support and information. All of our patient leaflets are available to read as well as downloadable in PDF format from this website. Resources for GPsEndotext.org 'Your Endocrine Source'
www.endotext.org (www.endotext.org/neuroendo/index.htm) Oxford Handbook of Endocrinology OUP (2002) JAH Wass & H Turner (Eds). More Specialist ResourcesManagement of Pituitary Tumors: The Clinician's Practical Guide (2003) (Second Edition), Editors and authors Michael P. Powell, Stafford L. Lightman and Edward R. Laws. Humana Press, Totowa, New Jersey Pituitary Tumours. Recommendations for service provision and guidelines for management of patients. Consensus statement of a working party (1997) RN Clayton & JAH Wass (Eds) London: Royal College of Physicians The Diagnosis and Treatment of Pituitary Insufficiency (1997) Lamberts SWJ (Ed) Bristol, UK: BioScientifica Endocrinology (1997) Levy A & Lightman SL New York: Oxford University Press The Epidemiology, Pathogenesis and Management of Pituitary Tumours (1998) Web SM (Ed) Bristol, UK: BioScientifica Oxford Textbook of Endocrinology OUP (2002) JAH Wass & S Shalet (Eds) NICE guidance of growth hormone in adults: www.nice.org.uk
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