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What is it?
Pituitary adenoma is a tumor of the hormone control center of the brain (pituitary gland) located between the eyes near the center and bottom of the brain. The average age of onset is 40 years old and affects women and men equally.
Pituitary adenomas can be secreting a hormone or non-secretory. If it is secretory, then presentation will depend on the hormone released. Non-secretory tumors present by causing pressure on the surrounding gland and neural structures, resulting in hypopituitarism and bitemporal hemianopsia (vision loss on both sides). Hair loss, lack of energy, loss of libido, infertility are signs of hypopituitarism. Pituitary adenomas secreting prolactin (PRL) present with amenorrhea (no periods) and galactorrhea (discharge from the breasts). Pituitary adenomas secreting adrenocorticotropin (ACTH), aka “Cushing’s disease,” present with hypertension (HTN), diabetes mellitus (DM), weight gain, and osteoporosis. Pituitary adenomas secreting growth hormone (GH) present with acromegaly (characteristic facial changes and increase in foot/hand size), hypertension, and DM. In children, GH adenomas cause gigantism. Left untreated, GH and ACTH secreting tumors shorten lifespan due to HTN and DM.
Characteristic findings mentioned above help establish the hormonal abnormality. Neurologic findings are worrisome for large tumors.
Magnetic resonance imaging (MRI) should include a high quality dedicated pituitary study with and without contrast. Visual field testing is advised for tumors suspected of compressing the optic chiasm. Comprehensive lab testing should include fasting glucose, 8AM cortisol, T4/TSH, PRL, FSH/LH, estradiol or testosterone, and IGF-1. Testing GH is not advised since it is unreliable. Additional tests may be required if abnormalities are found.
Bromocriptine/parlodel (5-7.5 mg/day) can lower PRL levels and shrink PRL secreting tumors. Prolonged treatment can reduce chances of surgical cure 50%. Tumor may still grow and stopping treatment will result in rapid tumor enlargement. Dostinex is another good medical choice (0.5-1 mg twice weekly).
For GH and ACTH adenomas, surgery is preferred. Sandostatin can help 70% of patients with GH adenomas and parlodel works 50% of the time. Somavert is another choice. Ketoconazole, cytadren, metopirone, lysodren, and periactin are options for ACTH adenomas with about 50% effectiveness.
For non-secretory tumors, hypopituitarism is managed with hormone replacement followed by surgery. Small tumors that are asymptomatic may be observed.
Indicated for patients who do not respond to medical management, have GH or ACTH adenomas, or have large tumors that compress surrounding structures. Transphenoidal approach (under the lip and through the nasal passage to the base of the skull) is the most common approach and is best performed by an experienced neurosurgeon/ENT team. The approach is well tolerated and presents lower risk than a craniotomy. Radiation therapy is recommended as a last resort or as adjuvant to surgery and is not the best first line treatment.
Outcome of Surgery
Complete excision of the tumor with preservation of normal pituitary function is the goal. Sometimes hormonal replacement is required for postoperative hypopituitarism. Tumor may extend into the cavernous sinus and require stereotactic radiation for tumor control. Recurrence rates of 12% 4-8 years after surgery mandates close follow-up after surgery with hormonal testing, MRI, and visual field testing. An aggressive, multi-specialty team approach affords the best outcome for patients with a pituitary adenoma.
We have the latest techniques and neurosurgical approaches available to us for your benefit. We take an aggressive approach to the treatment of Pituitary adenoma. We have the clinical experience for tumor-free long survivals and great hormonal control, all with a personal touch.