Thymic lesions of the paediatric age group: a comprehensive review of non-neoplastic and neoplastic etiologies

Thymus is an important part of the immune system of the paediatric age group. Thymic lesions are rare causes of anterior mediastinal pathology. Their occurrence in children is rarer, nevertheless, knowledge about their pathologies help in clinching the correct diagnosis. All lesions both non-neoplastic as well as neoplastic are found in children, however, they differ from adults not only in the clinical presentation but also in the pathogenesis and natural history of the disease. Thymic hyperplasia may not actually be true if age is taken into consideration. Similarly, a type B thymoma may be mistakenly diagnosed as a lymphoblastic lymphoma especially on small biopsies. This review has been carried out after extensive search of literature using the Google and Pubmed search engines. An attempt has been made to comprehensively cover all aspects of thymic pathology of the paediatric age group having historical significance as well as the recent updates.