Diagnosing Systemic Mastocytosis: State of the Art

With the advent of effective multikinase and selective tyrosine kinase inhibitors in systemic mastocytosis, diagnosing this rare disease has been critical to improving patient morbidity and mortality. This state‐of‐the‐art review interprets the international diagnostic criteria, including differences between the WHO 5th edition classification and the International Consensus Classification. Subclassification of systemic mastocytosis is critical for correct therapeutic strategies, and diagnostic difficulties are described for the practicing pathologist. Morphologic mimics, which require alternative treatment, are discussed.