Practice Essentials
The sellar region is a site of various types of tumors. Pituitary adenomas are the most common. They arise from epithelial pituitary cells and account for 10-15% of all intracranial tumors. Tumors exceeding 10 mm are defined as macroadenomas, and those smaller than 10 mm are termed microadenomas. Most pituitary adenomas are microadenomas. Pituitary imaging is important in confirming the diagnosis of pituitary macroadenoma and also for determining the differential diagnoses of other sellar lesions. Pituitary macroadenomas often require surgical extirpation for cure.
Signs and symptoms of pituitary macroadenomas
Patients with pituitary macroadenomas may be asymptomatic or may present with complaints due to hormonal imbalance or mass effects. The latter can be associated with visual deficits, headache, elevated intracranial pressure, and intracranial hemorrhage. Hormonally active tumors may present with symptoms due to target organ stimulation, such as hyperthyroidism, Cushing syndrome, or hyperprolactinemia.
Diagnosis and management of pituitary macroadenomas
All tumors should undergo screening basal hormone measurements, which may include prolactin, thyrotropin, thyroxine, adrenocorticotropin, cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, testosterone, growth hormone, insulinlike growth factor-1 (IGF-1), and alpha subunit glycoprotein.
Dynamic hormone tests are performed to assess the functionality of a tumor and assist in differential diagnosis. They also can be used to assess anterior pituitary reserve.
Pituitary imaging is important in confirming the diagnosis of pituitary macroadenoma and also for determining the differential diagnoses of other sellar lesions. Plain skull radiographs are poor at delineating soft tissues and so have been replaced by computed tomography (CT) scanning and magnetic resonance imaging (MRI).
Visual field testing should be performed, especially in tumors involving the optic chiasm. The severity of visual defects may dictate a more aggressive treatment course.
The goal of treatment for macroadenoma is complete cure. When this is not attainable, reducing tumor mass, restoring hormone function, and restoring normal vision are attempted using medications, surgery, and radiation. Pituitary macroadenomas often require surgical intervention for cure. The exceptions to this rule are the macroprolactinomas, which usually have an excellent response to medical therapy. The tumor size may be diminished but often does not disappear completely. Medical treatment can play a role in reducing tumor size, controlling hormonal excess, or correcting hormonal deficiency.