Multiple lymphomatous polyposis of the gut. A case with unusually widespread distribution.

Multiple lymphomatous polyposis (MLP) is a term used to describe malignant lymphomas of the gastrointestinal tract that manifest as polyposis. The cell population of MLP is identical to that in "mantle cell lymphoma." In most instances, relatively small segments of small and large intestine are affected. We report a case of MLP in which involvement was unusually widespread. A 56-year-old man, with abdominal pain and weight loss, proved to have a large mass at the ileocecal valve as well as multiple polyps of the stomach and small and large intestine. MLP is distinctive both grossly and microscopically. Clinically, it may be confused with epithelial polyps, and histologically it must be distinguished from benign lymphoid proliferations as well as other types of lymphoma. The latter distinction is important because of the relatively poor prognosis (median survival of < 3 years).