Pituitary Adenoma - Causes and Symptoms

Causes

In most cases, pituitary adenomas arise spontaneously, meaning they are not inherited. The hypothesis underlying the onset of neoplasia consists in the intervention of some growth factors, which can favor the appearance of mutations in cells already genetically predisposed.

These genetic alterations determine a "monoclonal expansion of a cell leading to a" hyperplasia (increase in the number of cells), which can evolve into an adenoma if the cell cycle control mechanisms are defective. These genetic mutations, in the majority of cases, are acquired, which is why adenomas occur sporadically. However, there is a small percentage of cases that respect genetic inheritance. Familial forms of pituitary adenomas are congenital, linked to a family history and found in the context of well-defined clinical entities (example: familial gigantism or familial acromegaly). cases, always rare, the onset is connected to genetic syndromes, such as MEN-1 (multiple endocrine neoplasia type 1), Carney's complex and McCune-Albright syndrome.

Symptoms

The symptoms obviously vary according to the type of adenoma. The clinical picture depends on the growth of the tumor mass, with local symptoms due to the compression of the neighboring structures, but also on the ability or not to induce an alteration of the pituitary function (hypopituitarism, hormonal hypersecretion or hypersecretory syndrome). In many cases, adenomas pituitary glands are asymptomatic and the patient does not suspect their existence, so much so that they are often diagnosed by chance.
Pituitary adenomas can produce different symptoms, related to several factors:

• Pituitary hyperfunction: An excessively active hormone is released into the blood. Usually, patients have symptoms related to the action of the hormone, with alteration of the delicate hormonal balance that regulates the functions of our organism. This effect is typically produced by functioning adenomas.
• Pituitary hypofunction: may be due to the compression of the pituitary structures adjacent to the tumor mass (mass effect).
• Neurological signs (mass effect): non-functioning adenomas can remain silent, until they cause problems typically related to the size of the neoplastic mass. If they grow significantly, macroadenomas can compress the pituitary gland and structures that are located near the tumor. This effect can produce neurological disturbances, impaired visual field (if it compresses the optic chiasm, the crossing point of the optic nerves, it can even induce vision loss) or it can compress the pituitary gland and cause pituitary insufficiency. Functioning adenomas can also grow and reach large sizes, causing compression problems in addition to hormonal effects.