Pituitary Microadenoma
Definition
A pituitary microadenoma is a benign growth smaller than 10 mm. Microadenomas come from glandular tissue, and can form in many organs. The most common microadenomas are in the adrenal and pituitary glands. They also can form in the colon, thyroid, and kidneys. They do not spread to other parts of the body.
Causes
It’s unknown why microadenomas form.
Risk Factors
A family history of multiple endocrine neoplasia type 1 (MEN1) – a hereditary condition – can increase the chances of developing a pituitary microadenoma or other types of microadenomas in the endocrine system.
Symptoms
The symptoms of pituitary microadenomas can vary based on where they are in the body, and if they are secreting hormones. Symptoms may be caused by other health problems, and don’t always indicate that there is a microadenoma.
Symptoms may include:
- headache
- problems with eyesight
- dizziness
- nausea
- unexplained hair growth or loss
- weight changes
- menstrual or breast changes
- erectile dysfunction
Diagnosis
Your physician will ask you about the symptoms you are having, will take a detailed medical history, and will perform a physical exam. Your physician may refer you to an endocrinologist.
Tests you may have done will vary based on the suspected location of the microadenoma. Possible testing includes:
- blood tests
- urine tests
- visual field tests
- CT scan
- MRI
Treatment
There are various ways to treat microadenomas, and many of the treatments may be used together.
Treatment options include:
Medication
Medications that block hormone secretion can control symptoms and possibly shrink the microadenoma.
Radiation therapy
This treatment uses radiation to kill the microadenoma’s cells. Radiation therapy generally is only used when medication and surgery were unable to remove the entire adenoma.
The types used may include:
- conventional therapy
- stereotactic radiosurgery
- proton beam radiotherapy
Surgery
The most common treatment for a pituitary microadenoma is removal. An exception to this is with a prolactin-producing tumor; that microadenoma is better treated with medication. Macroadenomas may be removed using either the expanded endoscopic approach (EEA) or through neuroendoscopic surgery.
The EEA uses a specially designed endoscope, which is a tubular device inserted through the nose that provides optical fiber light and a lens for seeing and transmitting images. Finely-crafted drills and other instruments are used with the endoscope for dissection and tumor removal.
This procedure gives surgeons access to the central brain, base of the skull, and the top of the spinal cord. Patients usually stay in the hospital for one or two days after surgery.
Prevention
Because the causes of pituitary microadenomas are largely unknown, there aren’t guidelines for preventing them.