title: What to do with incidental thyroid nodules identified on imaging studies? Review of current evidence and recommendations.
abstract: OBJECTIVE
  To discuss the problem of incidental thyroid nodules (ITN) detected on imaging; summarize the literature for workup methods; and provide recommendations based on current evidence.
  
  
  RESULTS
  ITN are a common problem, seen in 40-50% of ultrasound and 16% of computed tomography (CT) and MRI studies that include the thyroid. The personal and financial costs of workup frequently outweigh the benefits when considering that the majority of ITN are benign; 25-41% of patients undergo surgery after biopsy, of which more than half ultimately result in a benign diagnosis, and small thyroid cancers have an indolent course. Workup should consider reduction in unnecessary workup in addition to cancer diagnosis. The Society of Radiologists in Ultrasound recommendations have been proposed for ITN detected on ultrasound and found to reduce workup by 30%. For ITN detected on CT, MRI, or PET/CT, a three-tiered system categorization method reduces workup of ITN by 35-46%.
  
  
  CONCLUSIONS
  The ideal approach to selecting ITN detected on imaging for workup would not be to diagnose all cancers, but to diagnose cancers that have reached clinical significance, while avoiding unnecessary tests and surgery in patients with benign nodules, especially those who have limited life expectancy. The three-tiered system and the Society of Radiologists in Ultrasound recommendations are supported by existing studies and focus on reducing unnecessary biopsy.
authors.affiliation: aDepartment of Radiology bDepartment of Radiation Oncology, Duke University Medical Center, Durham, North Carolina cDepartment of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors.forename: Jenny K
authors.initials: JK
authors.lastname: Hoang
authors.forename: Allen T
authors.initials: AT
authors.lastname: Grady
authors.forename: Xuan V
authors.initials: XV
authors.lastname: Nguyen
mesh_terms: D044963:Biopsy, Fine-Needle; D019317:Evidence-Based Medicine; D006801:Humans; D033162:Incidental Findings; D008279:Magnetic Resonance Imaging; D049268:Positron-Emission Tomography; D017410:Practice Guidelines as Topic; D016606:Thyroid Nodule / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed