Pathology and molecular pathology of soft tissue sarcomas

Soft tissue sarcomas are rare compared to other malignancies such as carcinomas and represent approximately 1 % of all malignant neoplasms. The current World Health Organization (WHO) classification from 2013 defines more than 60 different entities. This article describes the histomorphological and molecular findings which are important for the current diagnostics of sarcomas. Most notably molecular diagnostic procedures have an increasing influence on the subtyping of sarcomas which requires a broad panel of molecular procedures and a sufficient number of sarcoma cases to be able to establish the correct diagnosis. Besides the relevance of molecular diagnostics to establish the correct diagnosis, the results are becoming increasingly more important to identify potential therapeutic targets. In the case of already existing specific inhibitors these may also be used in sarcoma patients. This implies that the sarcoma diagnosis has been done correctly and that patients with a specific sarcoma subtype can be identified through a central registry to be included in a clinical trial. A second opinion by a reference pathologist and the inclusion in such a registry should be the rule.