Types of Pituitary Adenomas

Pituitary adenomas are tumors that develop on the pituitary gland, a tiny, pea-sized organ at the base of the brain that produces hormones that travel throughout the body. The majority of pituitary adenomas are benign (not cancerous) and grow slowly. Pituitary adenomas can be classified in several ways, including by their size, whether they produce hormones and whether they are cancerous.

Microadenomas vs. macroadenomas

Pituitary adenomas are often categorized by their size. By this measure, there are two types of pituitary adenomas. Pituitary tumors that are smaller than 1 centimeter are called microadenomas, and those larger than 1 centimeter are called macroadenomas. Most pituitary adenomas are microadenomas. They are typically functional tumors, meaning they secrete hormones. Hormone secretion can cause symptoms to develop based on the specific hormone that the tumor produces, which often leads to the tumor being diagnosed.

Macroadenomas are typically nonfunctioning, meaning they do not produce hormones. However, macroadenomas can put pressure on surrounding pituitary cells, causing them to not function properly – a condition known as hypopituitarism that can lead to increased tiredness, low blood pressure and a change to sex drive and function.

Pituitary carcinomas

Pituitary carcinomas are an uncommon type of pituitary adenoma in which the cancerous cells have spread beyond the pituitary gland. Pituitary carcinomas are uncommon and may be difficult to treat. Most treatments for pituitary carcinomas are aimed at improving the patient’s quality of life and easing the symptoms caused by their tumor. Most often, surgery or radiation therapy may be used to slow the tumor’s growth, while medication is also used to manage the hormone levels if the pituitary carcinoma is functional.

As a high-volume cancer center, Moffitt Cancer Center is home to specialized oncologists who are highly experienced in treating all types of pituitary adenomas. If you would like to speak to a Moffitt oncologist about your pituitary tumor, request an appointment by calling 1-888-663-3488 or submitting a new patient registration form online. Referrals are not required to come to Moffitt.