Professor Peter Clayton
University of Manchester

Craniopharyngiomas, gliomas (optic nerve), astrocytomas and germinomas are types of tumours that can occur in the hypothalamic pituitary area. Craniopharyngiomas are rare benign tumours derived from remnants of Rathke's pouch and are made of solid tissue, cysts and calcified nodules. They occur within or above the pituitary and cause problems through the effects of pressure, hormones and the Hypothalamus.

Pressure effects can include headaches, vomiting and visual difficulty. Abnormalities are often first detected at the opticians, followed by hospital referral for head scanning and diagnosis. Hormonal effects can show as growth failure, puberty problems (late and early), tiredness and Diabetes Insipidus (DI), a condition where there is a reduction or loss in the secretion of Anti-diuretic Hormone (Vasopressin).

Hypothalamic effects are evidenced by dysregulation of appetite, temperature control, memory and mood. In a sample of 82 children presenting with craniopharyngiomas, 71 suffered headaches, 55 had visual loss, 45 had endocrine deficiency, 21 had DI and 12 showed personality changes. Hypothalamic (Hpa) tumours are diagnosed from the above symptoms, followed by detection of the tumour by a brain scan. Hpa tumours are treated with surgery (including in some cases shunt insertion to control hydrocephalus), Radiotherapy, chemotherapy and very occasionally by observation alone if the tumour is very small, within the pituitary and not pressing on vital structures. Radiotherapy may have side effects such as sickness and headaches. Hormones such as Cortisol, Growth hormone (GH), anti-diuretic hormone (ADH or vasopressin), Thyroxine and Oestrogen/Testosterone are replaced if deficient.

In a recent survey, craniopharyngiomas were treated by surgery in only 59% of cases and surgery plus dexamethasone (DXT) in 41% of cases. The recurrence or regrowth of tumour residue is dependent on tumour type. Gliomas can be slow growing while germinomas may be more malignant. Post-operative radiotherapy has been shown to prevent recurrence and should be recommended for those with tumour residue after surgery. Regular post-operative head scans are required, particularly if there are changes in symptoms.

In the immediately post-operative period, patients may experience transient or permanent DI. Patients are usually given high-dose potent steroids (DXT) to reduce tissue swelling around the tumour. Longer-term assessment of pituitary function and residual tissue will be required. Fluid balance, appetite, somnolence and temperature will also be monitored.

Hormone replacement can include GH, Desmopressin (DDAVP) for DI, Hydrocortisone, cortisol, thyroxine and/or Sex hormones for puberty and beyond. Treatment is monitored approximately four-monthly, with hand X-rays to assess bone age (and hence bone maturity) yearly. Puberty treatment starts at approximately 11-12 years for girls and 13 years for boys. This is an important time for rapid growth, physical development and significant increases in bone mass.

Hypothalamic damage can lead to the disruption of central appetite centres and abnormal vagus nerve function in the pancreas. This results in increased insulin secretion, which enhances appetite, fat storage and obesity and patients can gain weight very quickly after tumour treatment. Families and carers should encourage patients to have a healthy diet and plenty of exercise. Octreotide treatment in hypothalamic obesity has led to some improvement in weight control.

In the years after tumour treatment, children will need help with education and modifications to family lifestyle may be needed. Help in school to aid vision and concentration should be sought. Look for ways to increase energy through exercise though some sports may not be advisable. Inter-current illness must be managed and appropriate medical help sought. If the child is off school with illness then higher doses of hydrocortisone should normally be given. Advice regarding this should be sought from the child's endocrine support team. Parents are advised to have a hydrocortisone injection available in the event of an emergency. Life-long hormone replacement and medical supervision will be required, which may affect the type of career a person can undertake. Issues such as fertility, and treatment to achieve this, will need to be discussed.