Pituitary tumors or pituitary adenomas refer to a mass or growth in the pituitary gland. They can be divided into carcinomas, invasive adenoma, and benign adenomas. Approximately 10 to 25 percent of all intracranial neoplasms are pituitary adenomas. It also has been estimated that the prevalence of pituitary tumors among the general population is about 17 percent. Pituitary adenomas that are non-secreting and non-invasive are considered to be benign. Tumors that are more than 10 millimeters or 0.39 inches in size are by definition, macroadenomas while those smaller than 10 millimeters are microadenomas.
Most pituitary microadenomas remain undiagnosed and is often found as an incidental finding or often referred to as incidentalomas. While common (as many as 1 in every 6 individuals in the general population), pituitary tumors that are clinically active requiring surgery are rare, only affecting 1 in 1000 individuals of the general population. The risk factors of pituitary tumors include multiple endocrine neoplasia, Carney complex, familial isolated pituitary adenoma, and genetic causes. The pituitary gland is often referred as the “master gland” as it controls most of the endocrine functions in the body through the secretion of various hormones.
The diagnosis of a pituitary tumor can be suspected based on the constellation of symptoms. To confirm, tests such as radiographic imaging of the pituitary gland and testing of hormone levels can be done. Treatment of a pituitary tumor depends on the type of tumor and size. It may involve the use of medications and surgery.
Symptom #1: Unexpected Lactation
Unexpected or abnormal lactation can be referred to as galactorrhea which is most commonly caused by hyperprolactinemia. Hyperprolactinemia occurs when the levels of the hormone prolactin is higher than normal. It can be caused by medication, pituitary tumors, or other sellar and suprasellar lesions.
Other less common causes include renal insufficiency, hypothyroidism, nipple stimulation, and pregnancy. Patients with prolactinomas (prolactin producing pituitary tumors) can be treated with dopamine agonisis such as cabergoline or bromocriptine.