Primary central nervous system mucosa-associated lymphoid tissue lymphoma--case report.

A 55-year-old woman presented with an extremely rare primary central nervous system mucosa-associated lymphoid tissue (MALT) lymphoma manifesting as seizure and was subsequently diagnosed with dural MALT lymphoma in the cranium. Magnetic resonance imaging revealed a left frontal dural mass with peritumoral edema. Histological examination of the dural mass confirmed MALT lymphoma and revealed infiltration of small cells with irregular nuclear borders and expression of a B cell marker (CD20) but absence of CD5, CD10, CD23, and cyclinD1. Reactive T-cell infiltration was also seen. Subsequently, local irradiation (40 Gy/20 fractions) was performed. Magnetic resonance imaging showed complete remission just after irradiation was completed. There was no evidence of systemic MALT lymphoma. There has been no recurrence for 3 years without additional therapy.