Malignant histiocytosis of the intestine: a T-cell lymphoma.

Malignant lymphoma complicating coeliac disease has been characterised on morphological and immunocytochemical grounds as malignant histiocytosis of the intestine (MHI). Fresh tissue from four cases of MHI was studied by means of a panel of monoclonal antibodies; in three cases tumour DNA was studied for immunoglobulin and T-cell receptor (TCR) gene rearrangement. Immunocytochemistry showed a T-cell phenotype in all four cases, confirmed by the demonstration of a rearranged TCR beta-chain gene in the three cases studied. Lymphoma complicating coeliac disease thus appears to be of T-cell, rather than histiocyte, origin.