Endocrine incidentalomas

Endocrine incidentalomas are very common in the practice of every physician, mostly primary care and family physicians. Incidentalomas are discovered in the thyroid, pituitary and adrenal glands during imaging studies performed for non-endocrine reasons. The aim of this review article is to familiarise health professionals with all three endocrine incidentalomas, and give some guidance on how to initiate the right endocrine workup.

We reviewed the most pertinent literature published on this topic through PubMed and Medline. We also discussed our own approach to incidentalomas in the endocrine clinic at Thomas Jefferson Hospital in Philadelphia.

Thyroid incidentalomas are very common, with a prevalence close to 50% on imaging studies. Thyroid-stimulating hormone (TSH) is the first test to obtain; if not suppressed, next step is fine-needle aspiration biopsy of any nodule above 1 cm and/or with suspicious ultrasound characteristics. Adrenal incidentalomas have a prevalence of almost 5%. All adrenal nodules above 4 cm should be resected. Regardless of the size, a workup for pheochromocytoma should always be done. Only hypertensive patients should be screened for primary hyperaldosteronism. Pituitary incidentalomas are also common, with a prevalence of 10-20%. All patients with pituitary masses should have a workup for hormonal hypersecretion. Only patients with macroadenomas will have additional screening for hypopituitarism and visual field defects. All hyperfunctioning adenomas are resected except prolactinomas which are treated medically. Similarly, if a macroadenoma is causing hypopituitarism or visual deficit, surgery should also be considered.