Mastocytosis represents a heterogeneous group of neoplastic mast cell disorders. The basic classification into a skin-limited disease and a systemic form with multi-organ involvement remains valid. Systemic mastocytosis is a disease often hard to diagnose, characterized by different symptoms originating from either the release of mast cell mediators or organ damage due to mast cell infiltration. Gastrointestinal symptoms represent one of the major causes of morbidity, being present in 60-80% of patients. A high index of suspicion by clinicians and pathologists is required to reach the diagnosis. Gastrointestinal mastocytosis can be a challenging diagnosis, as symptoms simulate other more common gastrointestinal diseases. The endoscopic appearance is generally unremarkable or nonspecific and gastrointestinal mast cell infiltration can be focal and subtle, requiring an adequate sampling with multiple biopsies by the endoscopists. Special stains, such as CD117, tryptase, and CD25, should be performed in order not to miss the gastrointestinal mast cell infiltrate. A proper patient's workup requires a multidisciplinary approach including gastroenterologists, endoscopists, hematologists, oncologists, and pathologists. The aim of this review is to analyze the clinicopathological features of gastrointestinal involvement in systemic mastocytosis, focusing on the relevance of a multidisciplinary approach.
Keywords: bone marrow; gut; mast cell; mast cell activation; mastocytosis.