Pituitary Stalk Lesions

Overview

Pituitary stalk lesions are any abnormalities—for example, a tumor or inflammation—that affect the pituitary gland stalk. This thin structure comprises blood vessels and nerves that connect the hypothalamus to the pituitary gland. 

The pituitary stalk plays a crucial role in hormone signaling between the brain and the pituitary gland. It helps regulate essential body functions like growth, stress response, reproductive hormones, and water balance. Lesions in the pituitary stalk can disrupt the signaling pathway, leading to hormonal imbalances and visual or neurological symptoms. 

Pituitary stalk lesions can range from small, benign or non-cancerous conditions to more serious malignant or cancerous growths. They fall into one of three categories:

• Congenital lesions: These lesions are present at birth and are often diagnosed in childhood or adolescence, especially when puberty is abnormal. 
• Infectious lesions: These lesions are caused by infections that spread to the brain or meninges, and they can involve the stalk, especially in individuals with compromised immune systems. 
• Neoplastic lesions: These lesions are tumorous, where more than one tumor can originate from or involve the pituitary stalk.

What causes pituitary stalk lesions?

Several different conditions can cause pituitary stalk lesions. 

Some are inflammatory or autoimmune, like hypophysitis, which is more common in women during or after pregnancy, or sarcoidosis, a systemic inflammatory disease that can involve the pituitary gland and hypothalamus and cause a thickening of the pituitary stalk. 

Others are infectious, like tuberculosis or fungal infections that spread to the brain or meninges, especially in people with compromised immune systems or those who live in developing countries. 

Some tumors, including germinomas, craniopharyngiomas, and pituitary tumors, can originate from or involve the pituitary stalk, either directly or by compressing it. Metastatic cancers, or cancers that spread from other parts of the body, can also spread to the pituitary stalk. 

Very rarely, congenital pituitary stalk lesions are present at birth and found in childhood or adolescence due to hormone deficiencies that affect growth. Traumatic brain injury (TBI), surgery, or radiation therapy can also inadvertently damage the pituitary stalk. 

Sometimes, doctors can’t find a cause for the lesion, even after extensive testing. These are known as idiopathic pituitary stalk lesions. In these cases, individuals are monitored closely with MRIs over time, as some will eventually reveal an underlying condition. 

If you or someone you know has a pituitary stalk lesion, you may experience a combination of the following symptoms:

• Arginine vasopressin deficiency (AVP-D): Formerly known as diabetes insipidus, AVP-D occurs when AVP production in the hypothalamus and the back of the pituitary gland is interrupted. This affects the body’s ability to regulate fluid balance and causes excessive thirst and frequent urination.
• Hyperprolactinemia: Compression of the pituitary stalk can interfere with prolactin production, leading to hyperprolactinemia. In women, hyperprolactinemia can cause irregular or absent periods, known as amenorrhea, and discharge from the breasts, called galactorrhea. In men, it can lead to decreased libido or erectile dysfunction. 
• Hypopituitarism: A rare condition in which the pituitary gland doesn’t make enough of one or more of the hormones it usually makes, hypopituitarism can lead to fatigue, weight gain, cold intolerance, low blood pressure, dizziness, loss of libido, infertility, or menstrual changes.
• Headache: This symptom can stem from inflammation or a pituitary stalk lesion pressing on nearby brain structures, depending on the size of the lesion.
• Visual disturbances: A pituitary stalk lesion can compress the nearby optic nerves, leading to loss of peripheral vision, blurry vision, or even double vision.
• Slow growth in children: Pituitary stalk lesions can interfere with growth hormone (GH) release, leading to poor gains in height and a delayed puberty. 
• Nausea, poor appetite, or weight loss: A pituitary stalk lesion that affects the hypothalamus can cause nausea, poor appetite, and weight loss without a change in diet or activity level. 
• Mood or cognitive changes: Because pituitary stalk lesions can put pressure on the hypothalamus and lead to hormonal imbalances, this, in turn, produces symptoms like fatigue, depression, apathy, or difficulty concentrating.
• Heat or cold intolerance: When temperature regulation by the hypothalamus is disrupted due to a pituitary stalk lesion, feeling too hot or too cold in everyday environments can occur.

If you’re experiencing symptoms similar to these that seem to affect multiple systems—for example, your energy levels, weight, mood, and menstrual cycle or libido—you should consult a healthcare professional. While these are common symptoms of other conditions, early detection and treatment of a pituitary stalk lesion can improve outcomes.

Pituitary Stalk Lesion Diagnosis

Diagnosing pituitary stalk lesions involves a step-by-step approach to determine what the lesion is, how it affects hormone function, and whether it needs to be treated immediately or monitored. 

Doctors use the following exams, tests, and imaging tests to diagnose a pituitary stalk lesion:

• Physical and neurological exam: First, your healthcare provider will ask about your symptoms, overall health, and family history. Next, they’ll complete an examination to assess your neurological function, including your reflexes, coordination, strength, and sensation.
• Magnetic Resonance Imaging (MRI): Imaging studies are crucial in visualizing the brain and identifying abnormalities like a pituitary stalk lesion. The most important tool in diagnosing a pituitary stalk lesion is magnetic resonance imaging of the brain, focusing on the hypothalamic-pituitary region. An MRI provides detailed images of the pituitary stalk and surrounding structures and can reveal thickening or enlargement, whether the lesion’s appearance changes with contrast administration (suggesting inflammation or a tumor), and the presence or absence of the posterior pituitary “bright spot”, which signals antidiuretic hormone (ADH) signaling disruption.
• Computed Tomography (CT) scan: Your doctor may recommend a CT scan if an MRI isn’t advisable, although CT scans are less sensitive to small and soft tissue lesions.
• Hormone testing: Because the pituitary stalk plays a vital role in hormone signaling, blood and urine tests will be done to measure your hormone levels. These tests will measure cortisol and ACTH, thyroid hormones, LH, and FSH, sex hormones like estradiol or testosterone, prolactin, growth hormone (GH), and AVP. Abnormal results help confirm that the lesion is causing hypopituitarism or neuroendocrine dysfunction and narrow down possible causes.
• Blood tests: Depending on what imaging and hormone tests suggest, your provider may also check for markers of inflammation, autoimmune conditions, and infectious causes, like tuberculosis, syphilis, or fungal infections.
• Lumbar puncture: Also known as a spinal tap, a lumbar puncture involves a needle inserted into your lower back to collect cerebrospinal fluid (CSF) to check for signs of infection, malignant or cancerous cells, and elevated protein or inflammatory markers. Doctors only perform a lumbar puncture when an inflammatory or infectious cause is suspected. 
• Biopsy: In rare cases, if a pituitary stalk lesion is unclear in origin, growing, or not responding to medical treatment, a biopsy of the pituitary stalk may be done. This delicate procedure is only performed when necessary for a definitive diagnosis. 

Depending on your symptoms and results, your provider may also request visual field testing done by an ophthalmologist or neuro-ophthalmologist to determine if a pituitary tumor has damaged optic nerves and caused vision problems. 

Once diagnosed, understanding the cause of your pituitary stalk lesion is essential, as a spectrum of treatment options is available.  

Nonsurgical treatment is more common overall, especially in cases where the lesion is small, inflammatory, or infectious. Typically, doctors reserve surgery for cases that are aggressive, compressive, or unclear in diagnosis.

Nonsurgical Treatments

Nonsurgical therapy tends to be the first-line approach for many pituitary stalk lesions, especially when they’re inflammatory, autoimmune, infectious, or small and asymptomatic. 

The nonsurgical procedures used to treat a pituitary stalk lesion can include: 

• Observation with close monitoring: For small, stable pituitary stalk lesions with mild symptoms or without hormonal deficits, regular MRI scans, bloodwork, and physical and neurological exams may be sufficient. 
• Hormone replacement therapy: This approach is used when a pituitary stalk lesion has caused hormonal deficiencies, like hypopituitarism, and replaces missing hormones like cortisol, thyroid hormone, growth hormone, sex hormones like estrogen or testosterone, and desmopressin. 
• Corticosteroids: These oral or intravenous corticosteroids are given to reduce inflammation and swelling of the pituitary stalk in autoimmune or inflammatory causes. Prednisone or high-dose dexamethasone is frequently used to improve symptoms and occasionally reverse hormonal abnormalities. It is then continued at a lowered dose or tapered off over time. 
• Immunosuppressive therapy: In autoimmune or chronic inflammatory diseases where corticosteroids are insufficient or not well tolerated, immunosuppressants, like methotrexate, azathioprine, or mycophenolate mofetil, may be used. These therapies require regular monitoring by specialists for side effects.
• Disease-specific medications: For infection-specific causes like tuberculosis, doctors may prescribe antituberculosis therapy and antifungal or antiviral drugs.
• Radiation therapy: A portion of pituitary stalk lesions, such as germinomas, lymphomas, or metastatic cancer, respond well to radiation and chemotherapy. Doctors often use radiation when surgery is not an option or tumor removal is incomplete, and the tumor continues to grow despite other treatments. Radiation therapy uses precisely aimed beams of radiation to destroy tumors in the body—while it doesn’t remove the tumor, radiation therapy damages the DNA of the tumor cells, which then lose their ability to reproduce and eventually die. This treatment is non-invasive, with no recovery time required. However, its tumor-shrinking effects may take months or even years to develop.
• Chemotherapy: Oncologists typically reserve chemotherapy for more aggressive or malignant pituitary stalk lesion cases that do not respond to other treatments. Doctors may give chemotherapy drugs orally or intravenously to inhibit the growth of cancer cells, sometimes in combination with surgery or radiation therapy.

Surgical Treatments

In some cases, surgery for a pituitary stalk lesion is necessary; particularly when the lesion is large or growing, causing rapid vision loss, strongly suspected to be a tumor, or when there’s diagnostic uncertainty. 

Surgical procedures used to treat a pituitary stalk lesion can include:

• Transsphenoidal surgery: As the most common surgical approach, in transsphenoidal surgery, a neurosurgeon removes the lesion through the nasal passages and the sphenoid sinus using a small surgical instrument and an endoscope or microscope for visibility and precision. Transsphenoidal surgery works best on small to medium-sized pituitary stalk lesions confined to the pituitary region or lesions compressing the pituitary stalk. A transsphenoidal approach is also minimally invasive with a shorter recovery time. 
• Craniotomy: Larger, more complex lesions may require the surgical opening of your skull, known as a craniotomy. During a craniotomy, a neurosurgeon makes an incision in the scalp, removes a portion of the skull, and accesses the brain to remove as much of the lesion as possible. Neurosurgeons use intraoperative imaging and highly specialized tools to visualize and safely remove the lesion. A craniotomy is only used in select, more complex pituitary stalk lesion cases when the lesion is high in the stalk or hypothalamus, beyond the reach of the transsphenoidal route. It’s also a more invasive surgical approach with a longer recovery time.
• Biopsy only: When a diagnosis is uncertain and treatment decisions depend on studying tissues or cells under a microscope, a biopsy may be done through a transsphenoidal or another minimally invasive endoscopic approach. 

Consistent follow-up care using MRI scans and endocrine evaluations will also be essential to treatment, as your lesion can change over time. 

One Central Location with Multiple Treatment Options

At Barrow Neurological Institute’s renowned Pituitary Center, we treat people with pituitary tumors and disorders in one robust location. And because our doctors and nurses treat more people with pituitary disorders than any other team in the Southwest U.S., you can rest assured that you’ll be in very experienced hands.