What's a Pituitary Adenoma?

A pituitary adenoma is relatively common and shows up in approximately 1 in 1,000 adults. In general, it's a benign and slow-growing tumor.
What's a Pituitary Adenoma?

Last update: 13 December, 2019

A pituitary adenoma is a slow-growing benign tumor. It originates in the cells that comprise the pituitary gland. This is a gland that regulates the function of other glands in the body, which makes it important. However, a pituitary adenoma is relatively common and occurs in approximately 1 in every 1,000 adults. There’s no distinction in terms of gender as they equally affect men and women. There’s a greater incidence between 30 and 40 years, in terms of age variables.

In general, it’s a benign and slow-growing tumor. Thus, pituitary carcinomas or malignant tumors are very unusual. We still don’t know the actual causes of pituitary adenoma. However, in some cases, it’s related to a genetic disease called Multiple Endocrine Neoplasia Syndromes.

Symptoms of pituitary adenoma

A person talking to their doctor and a blue head.

The main symptom resulting from these kinds of tumors is an alteration in the secretion of hormones. Depending on the incidence of tumors in the pituitary gland, they may produce too much of one or more hormones. Due to the alteration in the endocrine system, the symptoms may be:

  • Hyperthyroidism: The thyroid gland produces excessive amounts of hormones. (This symptom is quite unusual in those affected by a pituitary adenoma.)
  • Cushing syndrome: Here the level of cortisol, a hormone, is higher than normal.
  • Acromegaly: Children with a high level of growth hormone may suffer from gigantism. If it happens in an adult, there may be acromegaly.
  • Secretion and production of milk in both men and women.
  • Irregular menstrual periods in women due to an alteration of sex hormones.

In contrast, some specific symptoms occur when there’s a compression of brain structures due to a large pituitary tumor. They may include:

  • Visual disturbances such as double vision, loss of visual field, droopy eyelids or changes in color vision.
  • Headaches.
  • Tiredness and drowsiness.
  • A nasal flow of clear liquid.
  • Nausea and vomiting.
  • Problems with the sense of smell.

These symptoms could be of concern if they appear suddenly and simultaneously. Also, they could lead to pituitary infarction. If you notice any of these symptoms, make sure to see your doctor. 

Types of adenomas

We can classify pituitary adenomas according to size in the following manner:

  • Microadenomas: These are less than 3/8 inch.
  • Macroadenomas: These are larger than 3/8 inch. This type of adenoma often leads to a large deficit in one or more pituitary hormones.

Also, one can classify them according to whether they secrete hormones or not. According to these criteria, they may be functional if they secrete hormones by themselves. On the other hand, they’re non-functional adenomas if they don’t secrete hormones.


The chemical formula for cortisol.

Regarding diagnosis, a doctor must perform a physical examination to analyze if there are any problems with double vision and visual field. Also, lab technicians study the loss of lateral or peripheral vision and the ability to see in certain areas. Then, they perform an analysis of the endocrine function to look for any signs of hormonal excess or other irregularities. Thus, they can measure parameters such as elevated cortisol levels, Cushing’s syndrome or too much growth hormone.

The most relevant tests that help confirm the diagnosis are the visual field and CT and brain MRI.

Pituitary adenoma treatment

Overall, current therapeutic options include:

  • Pharmacological treatment and hormone replacement: Medicines that block hormonal secretion can control symptoms and even reduce the size of a tumor.
  • Radiation therapy techniques: These are often used to decrease the size of a tumor.
  • Pituitary adenoma surgery: These tumors are usually removed through the nasal cavity. However, in other cases, doctors may need to do a craniotomy or opening of the skull.
  • Endoscopic nasal surgery consists of introducing an endoscope through the nostrils and sliding it between the middle turbinate and the nasal septum until they locate the sphenoid hole. This hole enlarges to achieve a sufficient opening of the sphenoid sinus and to be able to visualize the floor of the sella turcica to remove the tumor.

Blindness is the most serious complication if there is severe damage in the optic nerve. Also, the tumor or its excision could cause hormonal imbalances for life and lead to Diabetes insipidus. The characteristic symptoms for this type of diabetes are frequent urination and extreme thirst.

In any case, it’s important to seek treatment as early as possible if you notice any of the above symptoms. 

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Most pituitary adenomas are benign and slow-growing. You can identify them because they remain inside the pituitary gland or in its adjacent tissue...

  • Jaime, M. de, López, F., & Cabrera, G. (2003). Patología de los adenomas hipofisarios. Patología.

  • Betanzos, R. R., Gerardo, E., Pérez, D., Apolonia, S., Montaño, A., Sánchez, V., … Mendoza, C. (2009). Artículo de revisión Acromegalia. Mcm.