Signs and Symptoms of Pituitary Tumors

Not all pituitary tumors (pituitary adenomas) cause symptoms. But when they do, they can cause symptoms in these ways:

• Some tumors cause symptoms when they make too much of one or more pituitary hormones. These are called functional (or functioning) pituitary adenomas, and the symptoms they cause depend on which hormone(s) they make. These tumors tend to cause symptoms while they are still small.
• Tumors that don’t make enough hormones to cause symptoms, called non-functional (or non-functioning) adenomas, can become large enough to press on (or grow into) nearby structures, such as parts of the brain, nearby nerves, or other parts of the pituitary gland itself.

Symptoms caused by larger tumors

The pituitary gland sits in a very small space at the base of the skull. Pituitary tumors that grow large enough can press on or grow into nearby parts of the brain, nerves involved with vision, or other important structures. This can lead to symptoms such as:

• Trouble with eye movement, which can lead to blurred or double vision
• Visual field defects (especially loss of peripheral vision)
• Progressive blindness
• Headaches
• Facial numbness or pain
• Dizziness
• Loss of consciousness (passing out)

Tumors that grow large enough can also press on and destroy the normal parts of the pituitary gland. This can lead to low levels of one or more pituitary hormones, which can in turn lead to low levels of some body hormones such as cortisol, thyroid hormone, and sex hormones. Depending on which hormones are affected, symptoms might include:

• Feeling tired or weak
• Unexplained weight loss or weight gain
• Low blood pressure
• Loss of body hair
• Feeling cold
• Menstrual changes or loss of menstrual periods in women
• Erectile dysfunction (trouble with erections) in men
• Growth of breast tissue in men
• Decreased interest in sex

Diabetes insipidus

Large tumors can sometimes press on the posterior (back) part of the pituitary, causing a shortage of the hormone vasopressin (also called anti-diuretic hormone or ADH). This can lead to diabetes insipidus. In this condition, too much water is lost in the urine, so the person urinates often and becomes very thirsty as the body tries to keep up with the loss of water.

If left untreated, this can cause dehydration and altered blood mineral levels, which can lead to coma and even death. Diabetes insipidus can be treated by replacing vasopressin with a drug called desmopressin. (Diabetes insipidus is not related to diabetes mellitus, in which people have high blood sugar levels.)

Pituitary apoplexy

Another way that a pituitary tumor (especially a larger one) can cause many of the symptoms above is if it leads to bleeding or a blockage in a blood vessel, reducing the blood supply to the pituitary. This condition, known as pituitary apoplexy, isn’t common, but it can result in symptoms developing quickly, and it's often a medical emergency.

Symptoms caused by tumors making excess hormones

Symptoms from excess pituitary hormones depend on which hormone(s) the tumor is making. (Even when a tumor makes excess hormones, it might still cause some of the symptoms above, such as vision changes or headaches.)

Growth hormone-secreting adenomas (somatotroph adenomas)

The effects of tumors making too much growth hormone (GH) are different in children and teens from those in adults.

In children and teens, high GH levels can stimulate the growth of nearly all bones in the body, which is known as gigantism. Signs and symptoms can include:

• Being very tall
• Very rapid growth
• Joint pain
• Increased sweating

In adults, the arm and leg bones can’t grow any more, even when GH levels are very high, so people don’t grow taller. But the bones in an adult's hands, feet, and skull can grow throughout life. Making too much GH as an adult causes a condition called acromegaly. Signs and symptoms can include:

• Growth of the hands and feet
• Changes in how the face looks (due to growth of facial bones)
• Wider spacing of the teeth and protruding jaw (due to jawbone growth)
• Deepening of the voice
• Thickening of the tongue and roof of mouth, leading to sleep disturbances such as snoring and sleep apnea (pauses in breathing)
• Thickened skin
• Increased growth of body hair
• Numbness or tingling in the hands or feet
• Carpal tunnel syndrome
• Joint pain
• Increased sweating
• High blood sugar or even diabetes mellitus
• High blood pressure
• Heart disease

Many of these changes can occur very slowly, and people might not notice them until they look at an old picture of themselves or try to put on a hat, ring, gloves, or shoes they haven’t worn in many years.

Corticotropin (ACTH)-secreting adenomas (corticotroph adenomas)

High ACTH levels cause the adrenal glands to make excess steroid hormones such as cortisol. This causes symptoms that doctors group together as Cushing’s disease. In adults, the symptoms can include:

• Unexplained weight gain (mostly in the face, chest, and belly)
• Purple stretch marks on the chest or belly
• New or increased hair growth (on the face, chest, and/or belly)
• Swelling and redness of the face
• Acne
• Extra fat on the back of the neck
• Moodiness or depression
• Easy bruising
• High blood sugar levels or even diabetes mellitus
• High blood pressure
• Decreased interest in sex
• Changes in menstrual periods in women
• Weakening of the bones, which can lead to osteoporosis or even fractures

Most of these symptoms can also occur in children. Children with Cushing’s disease may also stop growing and have problems with school performance.

Prolactin-secreting adenomas (prolactinomas or lactotroph adenomas)

Prolactinomas are most common in young women and older men.

• In women before menopause, high prolactin levels cause menstrual periods to become less frequent or to stop. High prolactin levels can also cause abnormal breast milk production, called galactorrhea.
• In men, high prolactin levels can cause breast growth and milk production, as well as erectile dysfunction (trouble with erections)
• Both men and women can have loss of interest in sex, infertility, and weakening of the bones (osteoporosis).

These tumors can also sometimes grow large enough to press on nearby nerves and parts of the brain, which can cause headaches and vision problems. In females who don’t have periods (such as girls before puberty and women after menopause), prolactinomas might not be noticed until they grow large enough to cause these symptoms.

Thyrotropin (TSH)-secreting adenomas (thyrotroph adenomas)

These rare tumors make too much thyroid-stimulating hormone (TSH), which then causes the thyroid gland to make excess amounts of thyroid hormones. This can cause symptoms of hyperthyroidism (overactive thyroid), such as:

• Rapid or irregular heartbeat
• Tremors (shaking)
• Weight loss
• Increased appetite
• Feeling warm or hot
• Sweating
• Trouble falling asleep
• Anxiety
• Frequent bowel movements
• A lump in the front of the neck (from an enlarged thyroid)

Gonadotropin-secreting adenomas (gonadotroph adenomas)

These tumors make luteinizing hormone (LH) and/or follicle-stimulating hormone (FSH).

Most gonadotropin-secreting adenomas don’t make enough hormones to cause symptoms, so they are basically non-functional adenomas. These tumors may grow large enough to cause symptoms such as headaches and vision problems before they are found. (See "Symptoms caused by larger tumors" above.)

By pressing on the rest of the pituitary, these tumors can also sometimes result in lower levels of sex hormones such as estrogen, progesterone, and testosterone. This can lead to irregular menstrual periods in women or erectile dysfunction and decreased interest in sex in men.

Less often, gonadotroph adenomas do make excess hormones, resulting in higher levels of sex hormones. Most of these tumors occur in middle-aged adults, and the higher levels of hormones don’t usually result in any symptoms. But they might cause problems in younger people, such as irregular menstrual periods in younger women or early signs of puberty in girls.