The pituitary gland is a small, pea-sized structure situated at the base of the brain, often called the body’s master control gland because it produces hormones that regulate most other endocrine functions. An abnormal growth of cells within this gland is known as a pituitary tumor; the vast majority are non-cancerous growths called adenomas. These tumors cause significant health problems due to their location and ability to interfere with hormone production. Symptoms generally result from the tumor physically pressing on surrounding structures or from the excessive secretion of certain hormones.
Determining the Need for Surgery
The decision to proceed with surgical removal is based on a careful assessment of the tumor’s size, activity, and the symptoms it is causing. Doctors evaluate whether a tumor is causing physical compression on surrounding tissues (mass effect) or if it is actively producing excess hormones (hypersecretion). Prompt intervention is often necessary if the tumor is growing rapidly or causing immediate functional problems.
A common indication for surgery is when the tumor grows upward out of its bony cradle, the sella turcica, and begins pressing on the optic chiasm. This compression can lead to progressive vision loss, typically manifesting as defects in the outer peripheral fields. Removing the tumor relieves this pressure, which can rapidly improve or stabilize the patient’s sight.
Surgical removal is also the initial treatment for tumors that produce excess hormones, leading to conditions like Cushing’s disease or acromegaly. For example, in acromegaly, a growth hormone-secreting tumor causes the enlargement of hands, feet, and facial features; surgery quickly reduces the elevated hormone levels. While some hormone-secreting tumors, such as prolactinomas, are often first treated with medication, surgery becomes the preferred option if drug therapy fails to control hormone levels or shrink the tumor.
Non-functioning adenomas, which do not produce excess hormones, may still require removal if they grow large enough to cause mass effect symptoms like vision problems or severe headaches. Although slow-growing, these tumors account for a significant portion of pituitary surgeries when they impair the function of adjacent normal pituitary tissue. The size and invasiveness of the tumor, along with the patient’s overall health, ultimately guide the treatment plan.
Detailed Surgical Removal Techniques
The method used to remove a pituitary tumor is determined by its size, specific location, and how far it has spread into surrounding structures. The goal is to maximize tumor removal while minimizing trauma to the brain and remaining healthy pituitary tissue. Surgeons use advanced imaging, such as magnetic resonance imaging (MRI), to plan the safest route of access.
The most frequent method is the Transsphenoidal Approach, which avoids opening the skull entirely. This procedure is performed through the nasal cavity and the sphenoid sinus, located behind the nasal passages. The surgeon navigates this route to reach the sella turcica, the bony pocket where the pituitary gland sits.
Two variations are used: the microscopic and the endoscopic approach. The microscopic approach uses a specialized microscope to give the surgeon a magnified, illuminated view through a small incision inside the nose or upper lip. Alternatively, the endoscopic approach utilizes a thin, flexible tube with a camera and light at the tip, inserted directly through the nostril, providing a wider and more detailed view with less disruption to nasal structures.
During the transsphenoidal procedure, the surgeon makes an opening in the bone and membrane covering the gland to access the tumor. Specialized surgical instruments are then passed through the small corridor to carefully cut out and remove the abnormal growth. Since no part of the brain is touched, this technique generally results in a shorter hospital stay and faster recovery time.
The Craniotomy, or transcranial approach, is a more invasive procedure reserved for a small percentage of cases. This method involves opening a section of the skull, usually above the eyebrow or behind the hairline, to access the tumor from above or the side. Craniotomy is necessary only when the tumor is unusually large, has grown significantly into the brain tissue or surrounding blood vessels, or is difficult to remove through the narrow transsphenoidal corridor.
Immediate Post-Operative Care
Following pituitary tumor removal, the patient is closely monitored for the first 24 to 48 hours in an intensive care or step-down unit to ensure stability. Post-operative care focuses on managing pain, maintaining fluid balance, and monitoring neurological status. Patients typically receive temporary replacement doses of corticosteroids, such as hydrocortisone, because the remaining glands may not immediately produce enough cortisol to handle surgical stress.
A significant focus of care is monitoring fluid intake and output because the pituitary gland controls water balance. A potential complication is Central Diabetes Insipidus (DI), a temporary condition where the pituitary is unable to secrete sufficient Antidiuretic Hormone (ADH) due to surgical manipulation. This causes the kidneys to produce an abnormally large volume of dilute urine, which can quickly lead to dehydration and sodium imbalances.
Another concern after the transsphenoidal approach is the possibility of a Cerebrospinal Fluid (CSF) leak. This occurs when the barrier between the surgical site and the brain’s lining is breached, allowing the clear fluid surrounding the brain and spinal cord to drip from the nose. Surgeons seal this area with tissue or fat grafts, and patients are instructed to avoid activities that increase pressure, such as blowing their nose or straining, for several weeks.
The care team observes for symptoms of a leak, which increases the risk of infection like meningitis, alongside managing the patient’s sodium levels. Nasal passages may be congested due to swelling and packing material used during the procedure, and gentle nasal care with saline sprays is usually started shortly after surgery. The hospital stay for an uncomplicated transsphenoidal procedure is often only a few days.
Managing Hormonal Changes After Removal
Long-term management after pituitary surgery centers on assessing and managing the endocrine system, as tumor removal can affect hormone production by the remaining gland. Post-operative blood tests check the levels of pituitary-regulated hormones, such as cortisol, thyroid hormone, and sex hormones, to determine if the patient has developed hypopituitarism.
Many patients require Hormone Replacement Therapy (HRT) to substitute for hormones no longer adequately produced by the pituitary or its target glands. Cortisol replacement, usually oral hydrocortisone, is often the most urgent to manage, as its deficiency can be life-threatening. Patients must be educated on adjusting their hydrocortisone dose (“sick day rules”) to handle periods of physical stress or illness.
Replacement of thyroid hormone (thyroxine) is also frequently necessary to maintain proper metabolism, as is the replacement of sex hormones like testosterone or estrogen. While sex hormone replacement is not necessary for survival, it helps preserve bone density, energy, and sexual function. For children and sometimes adults, growth hormone may also be replaced.
Managing hormonal balance is a dynamic process that requires ongoing follow-up with an endocrinologist. While some temporary hormonal deficits may resolve over time, many patients require lifelong HRT. Regular blood testing, typically every few months initially, is necessary to fine-tune replacement doses and ensure optimal treatment.