title: Imaging findings of expansile lesions of the thymus.
abstract: The purpose of this article is to review the imaging findings of the different expansile lesions of the thymus. Almost 50% of all mediastinal masses are located in the anterior mediastinum. The thymus is the most common site of origin of these masses. Several kinds of lesions can arise from this gland because it derives from the three embryonic germ cell layers. Primary neoplasms of the thymus are thymoma, thymolipomas, carcinoma, carcinoid, primary germ cell tumors, and lymphoma. The latter can also involve the organ in a secondary fashion. Other lesions that cause thymic enlargement and that can be confused with neoplasia are thymic cysts and thymic hyperplasia. Even though anterior mediastinal masses are first found on conventional radiographs, computed tomography and magnetic resonance are very useful additional studies for assessing the origin and extension of these masses. The basic concepts regarding embryology, anatomy, and histology relevant for the differential diagnosis of an enlarged thymic gland are also described.
authors.affiliation: Department of Radiology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA. crestr@lsuhsc.edu
authors.forename: Carlos S
authors.initials: CS
authors.lastname: Restrepo
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Pandit
authors.forename: Isabel C
authors.initials: IC
authors.lastname: Rojas
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Villamil
authors.forename: Hernan
authors.initials: H
authors.lastname: Gordillo
authors.forename: Diego
authors.initials: D
authors.lastname: Lemos
authors.forename: Luciano
authors.initials: L
authors.lastname: Mastrogiovanni
authors.forename: Lisa
authors.initials: L
authors.lastname: Diethelm
mesh_terms: D003937:Diagnosis, Differential; D008206:Lymphatic Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008476:Mediastinal Cyst / Q000175:diagnosis / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic; D013950:Thymus Gland; D013953:Thymus Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed