[Primary pulmonary B-cell lymphoma of the MALT type].

The malignant B-cell lymphoma of the MALT-type shows significant differences from nodal lymphomas with respect to its biological, molecular genetic, and clinical properties. According to the proposal from the International Lymphoma Study Group for a Revised European-American Classification of Lymphoid Neoplasms, MALT-B-cell lymphomas have been defined as an extranodal subgroup of marginal zone B-cell lymphomas and may have lower and higher grade types. We have applied this classification to 24 cases of primary B-cell lymphomas of the lung. These tumors showed histopathologic features of low (n = 20) and/or high grade neoplasms (n = 4) recapitulating the structure of the acquired bronchus-associated lymphoid tissue (BALT). According to our experience, the diagnosis of BALT-type B-cell lymphoma, is both practically feasible and reproducible not only for surgical material but even for biopsy specimens.