Abstract
The importance of mast cells in the gastrointestinal tract is well known. In addition to their role in allergic reactions and in defense against microbial and parasitic infections, they also play an important role in regulating visceral sensitivity and vascular permeability.
Several studies have addressed the concentration of mast cells in the mucosa of patients with intractable cryptogenous chronic diarrhea and patients diagnosed with diarrhea-predominant irritable bowel syndrome. A new term, mastocytic enterocolitis, is used for a subset of patients with chronic intractable diarrhea with increased mast cells infiltration into the gut mucosa.
The etiology is unclear. It is also unclear whether the accumulation of mast cells in the intestinal mucosa is a consequence or cause of mucosal inflammation.
Regarding diagnosis, it is important to consider that intestinal biopsy samples may appear unremarkable on routine hematoxylin-eosin staining but show increased numbers of mast cells after immunohistochemistry for CD117 or mast cell tryptase. In this article we report the case of a 47-year-old female patient suffering from intractable diarrhea for 8 months, where the only pathologic finding was increased mast cell infiltration of gut mucosa.
The patient was successfully treated with topical corticoids and antihistamines.