Pituitary is a master endocrine gland situated in the head region. It secretes hormones which act as signaling molecules to other endocrine glands in the body. Most important hormones synthesized and secreted by pituitary gland are ACTH (adrenocorticotrophic hormone which acts on adrenal gland for cortisol production), TSH (thyroid stimulating hormone which acts on thyroid gland for thyroxine production) FSH and LH (follicular stimulating hormone and luteinizing hormone which act on testis in males and ovaries in females for testosterone or estrogen production and fertility) GH (growth hormone which is essential for growth) and prolactin (hormone required for milk production in females).
Tumors can arise in the pituitary gland and most of them are benign (non-cancerous). Decision to treat pituitary tumors depends on whether they are functional (hormone secreting) or nonfunctional (do not secrete hormones) and the size of the tumor. Tumors which are functional or large enough to compress vital structures in the surrounding (e.g. optic nerves) or those associated with symptoms like headache, vomiting, double vision etc. need surgical removal.
Cushings disease: ACTH producing tumors of pituitary cause Cushings disease. It is an excess cortisol state manifesting as obesity, diabetes, hypertension, muscle weakness, rounding of face, pink striae over abdomen, menstrual irregularities, unwanted hair growth in women and increased fragility of bones. There is also an increased risk of infections and neuropsychiatric manifestations like depression or psychosis in Cushings syndrome patients. Diagnosis is confirmed by high cortisol and high ACTH levels in the blood. Treatment involves surgical removal of the ACTH producing tumor by a neurosurgeon. In case of recurrence, re-surgery might be needed. Other modalities of treatment in recurrent Cushings syndrome include medical therapy and radiation.
Acromagaly:Acromegaly or acrogigantism is caused by growth hormone producing tumors of pituitary. Because of excess growth hormone levels the affected patients can be tall/giant (if occurring at a younger age) and have a characteristic features like enlarged nose, ears and lips, excessive sweating, increase in size of the fingers and increase in shoe size, severe headache, uncontrolled blood glucose levels, uncontrolled hypertension, joint pains, snoring, change in voice, cardiac complications like enlarged heart and heart failure. Diagnosis is confirmed by high IGF-1 levels and high GH levels after an oral load of glucose. Treatment includes surgical removal of the tumor and if high growth hormone levels persist after surgery, further treatment with drugs that inhibit growth hormone production or radiotherapy may be necessary.
Prolactinoma: Prolactinomas are one of the most common functional pituitary tumors. Commonest manifestations of prolactinomas in females are menstrual irregularities and milk discharge from breasts. In males it manifests with features of low testosterone levels i.e. loss of libido, erectile dysfunction, gynecomastia and infertility. Rarely they may present with headache, vomiting and visual disturbances especially if the size of the tumor is large. Prolactinomas are the only tumors of the pituitary gland where the first line of treatment is medical (and not surgery) irrespective of the size of the tumor. Drugs like cabergoline can affectively shrink the tumor and reduce prolactin levels. Tumors not responding to cabergoline may need surgical intervention.
Tumors of pituitary not associated with excessive production of hormones are called nonfunctional tumors and treatment depends primarily on the size of the tumor and presence or absence of pressure symptoms. Small sized tumors detected incidentally and not causing any pressure symptoms to the patient may be kept under active surveillance. An increase in size of these tumors on follow-up may require intervention. Large tumors may compress on the surrounding normal pituitary tissue resulting in hormone deficiencies which needs supplementation
