Pituitary tumors are abnormal growths found in the pituitary gland which makes hormones that affect growth and the functions of other glands in the body.
The pituitary gland is a pea-sized, reddish gray organ in the center of the brain, just above and behind the nose.
Pituitary carcinomas occur in both sexes, usually by the third or fourth decades of life. These tumors are quite common with 25% of people having small pituitary tumors on autopsy but most are symptom free and the vast majority of pituitary adenomas go undiagnosed throughout life.
Types of Pituitary Tumors
The types are named after the types of hormones the pituitary makes and include prolactin-producing adenomas, somatotrophin-secreting adenomas, corticotrophin-secreting adenomas, gonadotrophin-secreting adenomas, thyrotrophin-secreting adenomas, null cell adenomas, and adenomas of the mixed cell type. Another type of pituitary cancer shows up as very large hands, feet and face (acromegaly). The three tissue types of Pituitary tumours include; Chromophobe Adenoma (90%), Basophil Adenoma and Eosinophil Adenoma.
Although the exact cause is unknown, a predisposition to Pituitary tumors may be inherited through an autosomal dominant trait. Chromophobe adenoma may be associated with production of corticotrophin, melanocyte stimulating hormone, growth hormone and prolactin. Basophil adenoma with excess corticotrophin production and consequently with Cushings syndrome. Eosinophil adenoma with excessive growth hormone production.
Signs and Symptoms
As pituitary tumors grow they replace normal glandular tissue and enlarge the tissue that house the pituitary gland (sella turcica). The resulting pressure on adjacent intracranial structures produces the following typical symptoms: frontal headaches, vision problems, personality changes or dementia, seizures, head tilting and dizziness, strabismus, nystagmus, nausea and vomiting, or any of the problems caused by the production of too many hormones such as infertility or loss of menstrual periods in women, abnormal growth, high blood pressure, heat or cold intolerance, and other skin and body changes.
An MRI scan is now considered the imaging modality of choice for the diagnosis of pituitary disorders because of its multiplanar capability and good soft tissue contrast enhancement. The definitive diagnosis depends on the histological identification of the tumour found at surgery.
Treatment of pituitary neoplasms involves surgery, radiotherapy and drug therapy. Radiotherapy can be used as the primary treatment of pituitary tumours or as an adjunct to surgery. Medical therapy involves the replacement of hormones in hypopituitarism or suppression of hormone release in functional tumours.
Prognosis of Pituitary Cancer
Although prognosis depends on the type of pituitary tumor and the patient age and general state of health, pituitary tumors are usually curable, although many people will have to continue taking hormone replacements, sometimes for the rest of their lives.