Monoclonal gammmopathy (MG) in extranodal marginal zone lymphoma (ENMZL)

Marginal zone lymphoma of mucosa-associated lymphoid tissue with prominent plasma cell differentiation affecting the palatine tonsil: histopathological and immunohistochemical analysis

Non-Hodgkin lymphomas (NHLs) of the oral cavity and oropharynx constitute 13% of all primary extranodal NHLs. Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) in the palatine tonsil is rare, corresponding to 6% of the NHLs of the Waldeyer ring. Some cases of MALT lymphoma can present prominent plasma cell differentiation, and less commonly, monoclonal gammopathy. The differential diagnosis of these cases from other NHLs with plasmacytic differentiation or plasma cell neoplasms is very difficult. In this article, we describe a rare case of MALT lymphoma in a 34-year-old man presenting as a swelling of the palatine tonsil. The tumor mass was diagnosed as MALT lymphoma with prominent plasma cell differentiation. Systemic evaluation was noncontributory. This is the first report of MALT lymphoma showing extensive plasmacytic differentiation of the palatine tonsil, and reinforces a possible relationship between extramedullary plasmacytoma and MALT lymphoma.

[Monoclonal gammopathy and primary colonic mantle cell lymphoma]

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.