Rosai-Dorfman disease of the gastrointestinal tract: report of a case and review of the literature.

Rosai-Dorfman disease (RDD) is a rare, acquired disease of unknown etiology that affects primarily children and young adults. It is characterized by a proliferation of distinctive histiocytes in the lymph nodes and/or extranodal sites. Involvement of the gastrointestinal tract is rare. We report a case of RDD in a 60-year-old woman who presented with hematochezia and was found to have RDD of the rectum presenting as a rectal mass. This report highlights the current pathogenetic mechanisms, immunohistochemical markers, and the gastrointestinal manifestations of RDD. Int J Surg Pathol 14(1):95-99, 2006.