Pituitary Tumors

What is a Pituitary Tumor?

The vast majority of pituitary tumors (over 90%) are adenomas and are benign. However, due to their location, they can compress the optic nerves and surrounding brain structures. Tumors are classified as hormone-secreting (functional) or non-hormone-secreting (non-functional). Based on size, those smaller than 10 mm are called microadenomas, while those larger than 10 mm are called macroadenomas.

Pituitary tumors are quite common in the population and are incidentally detected in 10-25% of autopsy studies. Clinically symptomatic tumors occur at a rate of approximately 4-8 per 100,000 people annually. Although they can appear at any age, they are most commonly diagnosed between ages 30-60.

Types of Pituitary Tumors

Pituitary tumors are classified according to the type of hormone they produce:

Prolactinoma: This is the most common type of pituitary tumor, accounting for approximately 40% of all pituitary adenomas. It secretes excess prolactin and can cause menstrual irregularities and milk production in women, and sexual dysfunction in men.

Growth Hormone-Secreting Adenomas: By secreting excess growth hormone, they cause gigantism in children and acromegaly in adults. Abnormal growth of bones in the hands, feet, and face is observed.

ACTH-Secreting Adenomas: By increasing cortisol production, they lead to Cushing's disease. Weight gain, facial rounding, skin stretch marks, and hypertension are characteristic findings.

TSH-Secreting Adenomas: These are rare and cause excess thyroid hormone (hyperthyroidism).

Non-functional Adenomas: These tumors that do not secrete hormones usually remain asymptomatic until they grow large enough to compress surrounding structures.

Symptoms of Pituitary Tumors

Symptoms of pituitary tumors vary depending on whether the tumor secretes hormones and its size:

Hormone excess symptoms: Different hormonal syndromes occur depending on the tumor type. Milk production and cessation of menstruation in prolactinomas, enlargement of hands and feet in acromegaly, weight gain and purple stretch marks in Cushing's disease.

Mass effect symptoms: Large tumors can compress surrounding structures causing headaches, visual disturbances (especially peripheral vision loss), double vision, and pituitary hormone deficiency (hypopituitarism).

Hypopituitarism symptoms: May manifest as fatigue, weakness, sexual dysfunction, infertility, growth retardation, and thyroid dysfunction.

Pituitary apoplexy: Sudden bleeding or infarction within the tumor. Requires emergency intervention with severe headache, vision loss, and hormonal crisis.

Diagnostic Methods

Comprehensive evaluation is performed for pituitary tumor diagnosis:

Hormonal Tests: Blood tests measure all pituitary hormones (prolactin, growth hormone, IGF-1, ACTH, cortisol, TSH, T4, FSH, LH). Dynamic tests evaluate hormone excess or deficiency in more detail.

Magnetic Resonance Imaging (MRI): Pituitary MRI is performed with gadolinium contrast, and the tumor's size, extension, and relationship with surrounding structures are evaluated in detail. Thin-slice protocols may be required for microadenomas.

Visual Field Testing: Visual field evaluation is performed when there is compression of the optic nerves. Bitemporal hemianopsia (loss of outer vision in both eyes) is the classic finding.

Ophthalmological Examination: Visual acuity, fundus, and eye movements are evaluated.

Treatment Options

Pituitary tumor treatment is determined based on the tumor type, size, and patient's general condition:

Medical Treatment: Dopamine agonists (cabergoline, bromocriptine) are the first-choice treatment for prolactinomas, and tumor shrinkage is achieved in most patients. Somatostatin analogs can be used in acromegaly.

Surgical Treatment: Transsphenoidal surgery is a minimally invasive procedure performed through the nose and is the gold standard approach for pituitary tumor treatment. Endoscopic techniques offer less invasive and more successful results. Craniotomy may only be necessary for very large and complex tumors.

Radiation Therapy: Stereotactic radiosurgery (Gamma Knife, CyberKnife) or conventional radiotherapy is used for residual tumor tissue after surgery or in cases resistant to medical treatment.

Hormone Replacement Therapy: Replacement of deficient hormones is necessary in patients who develop hypopituitarism.

Prof. Dr. Salim Şentürk's Approach

Prof. Dr. Salim Şentürk adopts a multidisciplinary approach in the treatment of pituitary tumors. Each patient is evaluated together with endocrinology, neuroradiology, and when necessary, ophthalmology specialists. In cases requiring surgery, a minimally invasive approach is preferred using endoscopic transsphenoidal techniques.

Detailed hormonal and radiological evaluation is performed preoperatively. During surgery, neuronavigation and endoscopic imaging systems are used to enhance safety and effectiveness. Postoperative hormonal follow-up is conducted meticulously, and hormone replacement therapy is arranged when necessary.

Prognosis and Quality of Life

The prognosis for pituitary tumors is generally quite good. Complete treatment is possible in the vast majority of benign adenomas. The surgical success rate in microadenomas exceeds 90%. In macroadenomas, this rate varies depending on tumor size and extension.

With medical treatment for prolactinomas, tumor control and hormone normalization are achieved in most patients. Visual disturbances generally improve in patients who undergo surgery. With early diagnosis and appropriate treatment, the majority of patients achieve normal quality of life.

Regular follow-up is important for maintaining treatment success and early detection of possible recurrences. Hormonal balances are monitored with annual check-ups and MRI imaging.