title: Gastrointestinal abnormalities and involvement in systemic mastocytosis.
abstract: Recent studies have shown that involvement of the gastrointestinal tract is much more frequent than originally reported in patients with systemic mastocytosis. Seventy percent to 80% of patients with systemic mastocytosis are found to have gastrointestinal symptoms when a careful history is taken, and abnormalities in the gastrointestinal tract are frequently detected by endoscopic studies, functional studies of absorption, and barium studies. Because of the rarity of the disease, there are few prospective studies of gastrointestinal involvement, so the actual frequency of upper and lower gastrointestinal lesions is unknown. Furthermore, there have been no studies correlating endoscopic abnormalities of the lower gastrointestinal tract with the presence or absence of diarrhea, which is a frequent symptom (mean, 43% [range 14%-100%]). A review of gastric acid studies reveals that a proportion of patients develop gastric acid hypersecretion because of the hyperhistaminemia, which can result in ulcer disease that in turn can cause dyspeptic pain, small intestinal mucosal damage, and malabsorption. In some patients gastric acid hypersecretion in the range seen in Zollinger-Ellison syndrome can develop. A number of studies suggest that the prevalence of peptic ulcer disease has been underestimated in these patients and is certainly higher than the general population. The exact physiologic basis for the diarrhea or nondyspeptic abdominal pain remains largely unknown in these patients. Whereas some studies suggest small intestinal mucosal abnormalities are responsible for most cases of malabsorption not associated with gastric acid hypersecretion, this supposition also remains unproven. Hepatomegaly, portal hypertension, splenomegaly, and ascites occur frequently in patients with systemic mastocytosis, especially those with category II through IV disease. Whereas the histology of the liver and spleen and alterations in hepatic function studies have been well studied, the pathogenesis of each of these abnormalities has not been well studied, and almost all the information comes from a few well-studied case reports.
authors.affiliation: Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Jensen
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004205:Cromolyn Sodium / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D004064:Digestive System / Q000473:pathology*; D004802:Eosinophilia / Q000209:etiology; D004935:Esophageal Diseases / Q000209:etiology; D005744:Gastric Acid / Q000378:metabolism; D005767:Gastrointestinal Diseases / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology*; D006633:Histamine Antagonists / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use; D007413:Intestinal Mucosa / Q000473:pathology; D007422:Intestines / Q000473:pathology; D008107:Liver Diseases / Q000209:etiology; D008286:Malabsorption Syndromes / Q000209:etiology; D008415:Mastocytosis / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D011994:Recombinant Proteins; D013158:Splenic Diseases / Q000209:etiology; D014582:Urticaria Pigmentosa / Q000150:complications / Q000473:pathology
chemical_list: D006633:Histamine Antagonists; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D004205:Cromolyn Sodium