Thymic epithelial neoplasms: a review of current concepts using an evidence-based pathology approach.

Evidence-based pathology promotes the critical evaluation of current clinical information and the development of evidence-based diagnostic and prognostic guidelines. No randomized clinical trials of patients who have thymomas or thymic carcinomas are available to evaluate the validity of the current World Health Organization (WHO) histologic classification or the widely used Masaoka staging system. A meta-analysis of over 2000 thymoma patients estimated that only three WHO histologic types of thymomas are associated with significant survival differences. Prospective randomized clinical trials and an international registry of patients who have Thymic epithelial neoplasms are needed to stratify patients who may benefit from neoadjuvant chemotherapy, postoperative radiation therapy, and other nonsurgical modalities.