[613] Digestive Lesions in Systemic Mastocytosis. A Study of 23 Patients

D Canioni, H Sokol, N Hoyeau, S Barete, F Soppelsa, P Dubreuil, O Lortholary, O Hermine. Hopital Necker, Paris, France; Hopital Saint Antoine, Paris, France; Hopital La Pitié Salpetriere, Paris, France; AFIRMM, Paris, France

Background: Systemic Mastocytosis (SM) is characterized by accumulation and abnormal activation of mast cells in several organs. Gastro-intestinal (GI) symptoms and lesions have been poorly studied. The aim of this study is to describe the GI clinical symptoms and histological lesions in 23 patients with SM and to compare them to digestive biopsies of 19 healthy subjects (controls) and 17 patients with inflammatory bowel diseases (IBD) in order to evaluate their specificity.
Design: The 23 GI tract biopsies of SM patients from different sites (oesophagus to rectum) were studied on H&E staining and with CD117 and Tryptase antibodies and the number of mast cells (MC) was counted on 5 fields on high power view. Then, they were compared with the GI histology and immunohistochemistry the HS and IBD patients following same procedure.
Results: Digestive symptoms of SM patients were flush (45%), nauseas (45%), abdominal pain (59%) bloating (73%) and liquid stools (77%). Presence of GI symptoms was not correlated with c-kit mutation or high tryptase level. The number MC was increased in 78% of SM GI biopsies and this increase was slight in 27% of cases. Mast cells were also increased in controls and IBD (89% and 100%) but slightly comparing to SM patients (82% and 41%). The striking feature in SM GI biopsies was the repartition of MC in nests and their topography in the lamina propria (frequently around crypts or in villi tops). This feature was different from controls and IBD in which MC were scattered in lamina propria. The ratio MC/inflammatory infiltrate was also helpful for distinguishing SM from IBD patients since this ratio was in favour of MC in 74% of SM patients and in only 10% of IBD patients.
Conclusions: GI symptoms are highly prevalent in systemic mastocytosis. Histological lesions are not correlated with clinical symptoms in SM patients but they can be distinguished from those of controls and mainly IBD patients.
Category: Gastrointestinal

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 52, Wednesday Morning


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