Pituitary Incidentalomas

A pituitary incidentaloma is defined strictly as a totally asymptomatic tumour, clinically and biochemically silent, discovered incidentally in a patient who is asymptomatic or, less strictly, a pituitary mass discovered in the course of evaluation for an unrelated problem. The prevalence of pituitary incidentalomas found by computed tomography (CT) ranges from 3.7% to 20% and of those found by MRI is around 10%. Although the differential diagnosis is wide, the most common aetiology is pituitary adenoma. The diagnostic evaluation includes assessment for hormonal hypersecretion and for pressure effects by the lesion (mainly hypopituitarism and visual disturbance). Overall, the published data suggest that lesions smaller than 1 cm follow benign course. In contrast, masses bigger than 1 cm are associated with higher risk of enlargement often leading to pressure effects and requiring neurosurgical intervention. If surgery is not indicated, regular follow-up mainly with imaging is recommended. A safe and cost-effective protocol for this remains to be elucidated.