Practice Guidelines for Pituitary Incidentalomas
From ENDO 2010 The Endocrine Society Annual Meeting, San Diego, June 19-22, 2010
Clinical practice guidelines were highlighted at the Endocrine Society meeting and new evidence-based recommendations on the evaluation and treatment of pituitary incidentalomas were presented by Pamela Freda (chair of the task force that developed the guidelines). A pituitary incidentaloma is an incidentally discovered pituitary lesion. The true nature of pituitary incidentaloma usually remains unknown as most do not result in surgery. In the limited surgical cases available, pituitary adenomas are the most common etiology.
The guidelines recommend the initial evaluation of a patient with a pituitary incidentaloma to include laboratory screening for hormone hypersecretion in all incidentaloma patients, including those with and without symptoms. The task force debated the pros and cons of detailed versus limited screening for hormone hypersecretion ie, stimulation tests versus insulin-like growth factor (IGF)-I and midnight salivary cortisol levels. There was agreement on screening for prolactin, which should be measured in all incidentalomas.
The practice guideline also recommends initial routine screening for hypopituitarism in patients with macro-incidentalomas, both with and without symptoms, but not in all patients with micro-incidentalomas because the incidence of hypopituitarism is not high in these patients. However, the task force suggested screening might be done for patients with large micro-incidentalomas − in the range of 8 to 9 mm. Follow-up testing of pituitary function for hypopituitarism is indicated for patients with macro-incidentalomas 6 months after initial testing and then yearly. However, routine repeated functional testing is not required for patients with micro-incidentalomas when the patient's clinical picture, history and MRIs do not change over time.
Non-surgical follow-up is recommended with clinical assessments and functional testing for patients who do not meet criteria for surgical removal of the pituitary incidentaloma. As for follow-up imaging of non-surgically treated incidentalomas, the guideline recommends MRI of the pituitary in patients with macro-incidentalomas 6 months after the initial scan, and for patients with micro-incidentalomas, one year after the initial assessment.
Finally, the guidelines recommend that patients with pituitary incidentalomas be referred for surgery: if they have a visual field deficit or signs of compression by the lesion leading to other visual abnormalities; if the lesion abuts the optic nerve or optic chiasm on MRI; if they have pituitary apoplexy with visual disturbance; or if they are found to have a hypersecreting tumor other than a prolactinoma. Other indications for surgery suggested in the guidelines include clinically significant growth of the incidentaloma, loss of endocrine function and unremitting headache, or a lesion that is close to the optic chiasm when the patient is planning pregnancy.
Pamela Freda, MD. Chair of Task Force, Columbia University College of Physicians and Surgeons, New York, USA
Editor's Comment - (linked to )
The prevalence of pituitary incidentalomas will likely increase as there is more frequent use of brain scanning for multiple purposes. CT scanners first began to be installed in 1974 in clinical settings. Currently over 6000 scanners are in use in the US. The CT scan has become a commonly performed procedure. Scanners are found not only in hospital radiology departments, but also in outpatient offices. Usage of CT has increased dramatically over the last two decades.1 An estimated 72 million scans2 were performed in the US in 2007 - it is likely a higher number today. In Calgary Canada 12.1% of people who present to the emergency with an urgent complaint received a CT scan, most commonly either of the head or the abdomen. The percentage of patients who received CT scans, however varied markedly (1.8% to 25%), depending on the emergency physician who saw the patient.3 Thus, the practice guidelines are very timely. In children careful assessment of growth progression and sexual development should be evaluated, both at the time the incidentaloma is detected and closely monitored thereafter. Patients with pituitary incidentalomas may find it difficult to accept a wait and see plan without neurosurgical and ophthalmological input; these guidelines should help assure the patient and family.
Fima Lifshitz, MD