Pituitary Surgery


Pituitary Tumour
Causes and Risks

The pituitary gland is a pea-sized endocrine gland located at the base of the brain. The pituitary gland regulates and controls the secretion of hormones from other endocrine glands and many body processes by producing a range of hormones.

Pituitary tumours constitute 10% of primary brain tumours. Most are located in the anterior pituitary (adenohypophysis). Most of the tumours are not malignant, but because their growth invades other structures, the tumours are considered a neoplasm. As the tumour grows, destruction of some of the hormone-secreting cells takes place and symptoms of underproduction of the pituitary gland result (hypopituitarism).

Pituitary adenomas are the type of pituitary tumour that occurs in about 90% of cases, and the tumour may secrete hormones depending on the cell type of the adenoma. Some tumours produce an excess of certain hormones leading to gigantism or acromegaly (growth hormone excess), hyperthyrodism ( thyroid stimulating hormone excess), Cushing’s syndrome (adrenocorticotropic hormone excess), or prolactinoma ( prolactin excess). Craniopharyngiomas are benign , cystic, congenital tumours. The causes of pituitary tumours are unknown. The incidence is 1 out of 10,000 people.

Prevention

There is no known prevention.

Symptoms
  • headache

  • visual changes

  • double vision

  • drooping eyelids

  • personality changes

  • seizures

  • nasal drainage

  • cessation of menses

  • decreased sexual drive and impotence in men

  • skin changes

  • loss of body hair

  • weakness

  • lethargy

  • intolerance to cold

  • irritability

  • constipation

  • nausea

  • vomiting

  • low blood pressure

  • milk flow unrelated to childbirth or nursing ( nipple discharge, abnormal breast development in males)

Note: Symptoms are related to hormone deficiencies and pressure on intracranial structures.

Signs and Tests

A physical examination shows abnormal eye findings.

Tests that help confirm the diagnosis:

  • a cranial CT scan that shows a mass (aggregation of cells) consistent with pituitary tumour

  • skull X-ray

  • carotid angiogram

  • spinal tap for cerebrospinal fluid analysis

  • endocrine function tests

  • MRI of head that shows mass consistent with pituitary tumour

Treatment

Surgical treatment to remove the tumour may be done through the skull if the tumour is large and placing pressure on optic nerves. Transphenoidal resection (the tumour is accessed through the nose and sinuses) is a procedure used for smaller tumours. Radiation therapy may be used in combination with surgery, or for people who are poor surgical candidates. Certain medications may shrink certain types of tumours.

Prognosis

The probable outcome is fair to good depending upon the extent of tumour spread within brain structures.

Complications

Spread of the tumour to other brain structures can occur.


Further Information

The endocrine system is the chemical control centre of the body.

The pituitary gland is often considered the master control; sending out hormones that regulate the function of the thyroid, adrenal glands, ovaries, and testis.

Over- or under-production of hormones from any of these glands is associated with many different types of disease.