Primary leptomeningeal B-cell lymphoma of MALT-type in statu nascendi: a case report and review of the literature.

A 29-year-old Caucasian female suffering from bipolar disorder, mixed, moderate with psychotic features (DSM-IV 296.64) and panic disorder without agoraphobia (DSM-IV 300.01) died as a result of an accidental overdose. Upon histopathological examination of the brain, as an incidental finding, a small lesion (1mm x 2mm) composed of heterogeneous small lymphocytic cells (CD20-positive) including centrocyte-like cells, a few small lymphocytes and rare immunoblast-like cells was evident. The diagnosis of primary leptomeningeal MALT-type lymphoma was made. Due to its small size and lack of space-occupying characteristics, the lesion is considered to be in statu nascendi. This case adds another aspect to the rare entity of primary leptomeningeal lymphomas.