[Monoclonal gammopathy and primary colonic mantle cell lymphoma]. / Une gammapathie monoclonale associée à un lymphome colique primitif à cellules du manteau.

The association of a monoclonal gammopathy (MG) with a B cell non-Hodgkin's lymphoma (NHL) is a well-known phenomenon. It has been recognized in many subtypes of primary gastrointestinal lymphoma but its association with primary colonic mantle cell lymphoma has never been yet described. We report a 65-year-old man who presented with an exudative ascites and constipation. Serum electrophoresis showed a monoclonal peak in the gamma region of 45g/L and immunoelectrophoresis confirmed the presence of monoclonal gammopathy of IgM kappa type. Bone marrow aspirate was normal. Radiologic and endoscopic investigations evidenced a primary colonic mantle cell lymphoma. Although the association of an MG with an NHL and, in particular, to a primitive digestive location appears a rare phenomenon, endoscopic investigations in patients with MG appears legitimate in the presence of any digestive sign.