PURPOSE: As computed tomography (CT) scanning is increasingly used for the evaluation of many signs and symptoms, more patients are being found to have anterior mediastinal masses unrelated to the reason for which they are undergoing evaluation. There are a lack of established CT based guidelines for determining who should undergo invasive management or follow-up.The purpose of this study was to define CT characteristics of benign pathology in patients with anterior mediastinal masses using both two and three-dimensional data.
METHODS: Records and CT's of all patients referred for anterior mediastinal masses in the thoracic surgery clinic over the past 4 years were reviewed for several CT specific criteria. The study group consisted of 21 patients who had benign pathology (normal thymus or thymic hyperplasia) on invasive biopsy or resection (n=7) or were followed (n=14) with serial CT scans and ultimately have not required invasive management. The control group consisted of 21 patients who had pathology that required biopsy or resection.
RESULTS: No patients in the CT follow-up group have required invasive biopsy or resection. Age and body mass index were not significantly different between the two groups (mean follow-up 21.3 ± 16 months). CT parameters associated with benign lesions included midline centering, no extension below the AP window, concavity, area and volume, lack of cystic regions, and maintenance of the pleural angle. Patients in whom anterior mediastinal masses met 3 of 5 criteria were likely to have benign pathology.• Area < 597 mm2 AND Volume < 16.85 cc3• Midline• Maintenance of the pleural angle• Concavity• No extension below the AP window(sensitivity = 0.952, specificity = 0.905).
CONCLUSION: CT defined criteria may select patients with incidentally found anterior mediastinal masses who can be considered for observation instead of biopsy or excision.
CLINICAL IMPLICATIONS: CT defined criteria can be used to decrease invasive procedures in the setting of incidental anterior mediastinal masses.
DISCLOSURE: Matthew Blum, No Financial Disclosure Information; No Product/Research Disclosure Information