It has been over a decade since the last iteration of the World Health Organization (WHO) classification of head and neck tumors (the so called “blue book”). This time interval has brought several key changes to a broad variety of tumor types in the head and neck region to the point that the topic of envisioning future changes in the WHO was a focus of a North American Society of Head and Neck Pathology Companion Meeting, March 2, 2014, in San Diego, California [
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6]. Thus, the 4th edition of the WHO blue book is a crystallization of many of these predicted changes, and a welcome update. …