Pituitary adenomas part2, Physical Symptoms: Hormone secreting pituitary adenomas cause one of several forms of hyperpituitarism. The specifics depend on the type of hormone.
Pituitary adenomas part2: What are the specifics? Some tumors secrete more than one hormone, the most common combination being GH and prolactin. A pituitary adenoma may present with visual field defects, classically bitemporal hemianopsia. It arises from the compression of the optic nerve by the tumor. The specific area of the visual pathway at which compression by these tumours occurs is at the optic chiasma. The anatomy of this structure causes pressure on it to produce a defect in the temporal visual field on both sides, a condition called bitemporal hemianopsia. If originating superior to the optic chiasm, more commonly in a craniopharyngioma of the pituitary stalk, the visual field defect will first appear as bitemporal inferior quadrantanopia, if originating inferior to the optic chiasm the visual field defect will first appear as bitemporal superior quadrantanopia.
Pituitary adenomas part2: Effects beyond the pituitary
Lateral expansion of a pituitary adenoma can also compress the abducens nerve, causing a lateral rectus palsy. Also, a pituitary adenoma can cause symptoms of increased intracranial pressure. Prolactinomas often start to give symptoms especially during pregnancy, when the hormone progesterone increases the tumor’s growth rate. Various types of headaches are common in patients with pituitary adenomas. The adenoma may be the prime causative factor behind the headache or may serve to exacerbate a headache caused by other factors.
Pituitary adenomas part2: Types of headache
Amongst the types of headaches experienced are both chronic and episodic migraine, and more uncommonly various unilateral headaches; primary stabbing headache, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing – another type of stabbing headache characterized by short stabs of pain -, cluster headache, and hemicrania continua. Psychiatric Various psychiatric manifestations have been associated with pituitary disorders including pituitary adenomas. Psychiatric symptoms such as depression, anxiety apathy, emotional instability, easy irritability and hostility have been noted. Complications Acromegaly is a syndrome that results when the anterior pituitary gland produces excess growth hormone. Approximately 90-95% of acromegaly cases are caused by a pituitary adenoma and it most commonly affects middle aged adults, Acromegly can result in severe disfigurement, serious complicating conditions, and premature death if unchecked. The disease which is often also associated with gigantism, is difficult to diagnose in the early stages and is frequently missed for many years, until changes in external features, especially of the face, become noticeable with the median time from the development of initial symptoms to diagnosis being twelve years.
Pituitary adenomas part2: Hormonal disorders
Cushing’s syndrome is a hormonal disorder that causes hypercortisolism, which is elevated levels of cortisol in the blood. Cushing’s disease is the most frequent cause of Cushing’s syndrome, responsible for approximately 70% of cases. CD results when a pituitary adenoma causes excessive secretion of adrenocorticotropic hormone that stimulates the adrenal glands to produce excessive amounts of cortisol. Cushing’s disease may cause fatigue, weight gain, fatty deposits around the abdomen and lower back and face, stretch marks on the skin of the abdomen, thighs, breasts and arms, hypertension, glucose intolerance and various infections.
In women it may cause excessive growth of facial hair and in men erectile dysfunction. Psychiatric manifestations may include depression, anxiety, easy irritability and emotional instability. It may also result in various cognitive difficulties. Hyperpituitarism is a disease of the anterior lobe of the pituitary gland which is usually caused by a functional pituitary adenoma and results in hypersecretion of adenohypophyseal hormones such as growth hormone; prolactin; thyrotropin; luteinizing hormone; follicle stimulating hormone; and adrenocorticotropic hormone. Pituitary apoplexy is a condition that occurs when pituitary adenomas suddenly hemorrhage internally, causing a rapid increase in size or when the tumor outgrows its blood supply which causes tissue necrosis and subsequent swelling of the dead tissue. Pituitary apoplexy often presents with visual loss and sudden onset headache and requires timely treatment often with corticosteroids and if necessary surgical intervention. Central diabetes insipidus is caused by diminished production of the antidiuretic hormone vasopressin that causes severe thirst and excessive production of very dilute urine which can lead to dehydration. Vasopressin is produced in the hypothalamus and is then transported down the pituitary stalk and stored in the posterior lobe of the pituitary gland which then secretes it into the bloodstream. The diagnosis of CDI is based on the results of urine and blood tests, and a water deprivation test which tests the body’s ability to concentrate urine.
CDI is often treated with desmopressin acetate a synthetic vasopressin known as DDAVP administered via nasal spray. Diagnosis and workup Diagnosis of pituitary adenoma can be made, or at least suspected, by a constellation of related symptoms presented above. Tumors which cause visual difficulty are likely to be a macroadenoma greater than 10 mm in diameter; tumors less than 10 mm are microadenoma. The differential diagnosis includes pituitary tuberculoma, especially in developing countries and in immumocompromised patients. The diagnosis is confirmed by testing hormone levels, and by radiographic imaging of the pituitary. Treatment Treatment options depend on the type of tumor and on its size: Prolactinomas are most often treated with bromocriptine or more recently, cabergoline or quinagolide which decrease tumor size as well as alleviates symptoms, both dopamine agonists, and followed by serial imaging to detect any increase in size.
Pituitary adenomas part2: Treatment
Treatment where the tumor is large can be with radiation therapy or surgery, and patients generally respond well. Efforts have been made to use a progesterone antagonist for the treatment of prolactinomas, but so far have not proved successful. Somatotrophic adenomas respond to octreotide, a long-acting somatostatin analog, in many but not all cases according to a review of the medical literature. Unlike prolactinomas, thyrotrophic adenomas characteristically respond poorly to dopamine agonist treatment. Surgery is a common treatment for pituitary tumors. Trans-sphenoidal adenectomy surgery can often remove the tumor without affecting other parts of the brain. Endoscopic surgery has become common recently. See also Pituitary disease Pituitary tumour References External links Cancer.gov: pituitary tumors Cleveland Clinic: Evaluation and management of pituitary incidentalomas  The Pituitary Foundation.