Low-grade primary B-cell lymphoma of the lung. An immunohistochemical, molecular, and cytogenetic study of a single case.

A case of primary low-grade pulmonary lymphoma is described. The histologic features conformed to those laid down by Saltzstein for a diagnosis of "pseudolymphoma." However, the immunocytochemical and molecular investigations confirmed the tumor to be a low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). Cytogenetic studies revealed an abnormal karyotype with a translocation t(1;14). This is the first reported case of an abnormal karyotype in a case of a lymphoma of MALT.