What's new in small round blue cell sarcomas?

Establishing a specific diagnosis for a so-called “small round blue cell sarcoma” requires pathologists to consider a broad differential diagnosis and understand the nuanced histology of these tumours. Pathologists must guide the cost effective selection and appropriate interpretation of immunohistochemical and molecular tests in conjunction with histologic and clinical data. We present a review of common small round blue cell sarcomas, highlighting challenging histologic differential diagnoses and diagnostic pitfalls.