Pictorial Review of Extraosseous Ewing’s Tumour: A Single Center Experience

Abstract

Purpose: Ewing’s family tumour is an extremely rare tumour, with annual incidence rates amongst Caucasian children <21 years being in the range of 2–3 cases per million in the U.S. There are mainly three subtypes including Ewing’s sarcoma (ES) of bone, extraosseous (EO) Ewing’s tumour and Peripheral primitive neuroectodermal tumour. Although extremely rare, this study represents a review of various types of cases and the significance of imaging including its baseline and post-treatment response radiological characteristics. There are a very few cases of EO ES in the current literature with variable spectrum of tumour site and their imaging characteristics.Materials and Methods: Electronic records were retrospectively reviewed from 1 May 2011 to 1 May 2016 with patients who were diagnosed as histologically proven ES. A number of patients, gender and base line computed tomography (CT)/magnetic resonance imaging findings for staging were reviewed.Results: A total of 568 patients with diagnosed ES were analysed, of which 15 patients had EO type of ES. Of these only 8 patients had baseline imaging available which included tumours arising from the occipital region, orbit, anterior mediastinum, anterior abdominal wall, mesentery, kidney, prostate gland and presacral region.Conclusion: EO ES is a rare entity and can involve a wide array of soft tissue organs. A cross-sectional imaging with CT and MR has a key role in pre- and post-treatment assessment.Key words: Computed tomography, Ewing’s sarcoma, extraosseous Ewing’s, magnetic resonance imaging, peripheral primitive neuroectodermal tumour