Resection of the tumor was performed.

MACROSCOPIC DESCRIPTION: "Dural tumor": The specimen is roughly dome shaped with dura at the base. The cut surface has a uniform brown appearance.

MICROSCOPIC DESCRIPTION: The sections show a proliferation of atypical lymphoid cells, forming diffuse sheets. The atypical lymphocytes are small in size. They have mildly enlarged clefted and hyperchromatic nuclei, small nucleoli and scanty cytoplasm. Plasmacytoid cells are inconspicuous. Some entrapped lymphoid follicles are noted (bcl-6 positive, bcl-2 negative). The atypical lymphoid cells are CD20, PAX-5 and bcl-2 positive. Patchy weak CD23 staining is noted. The Ki-67 index is less than 10%. CD3, CD5, CD10, CD138, bcl-6, Cyclin D1, SOX-11, MUM1 and EBER-CISH are negative. The features are consistent with extranodal marginal zone lymphoma.

DIAGNOSIS: Features consistent with extranodal marginal zone lymphoma.

Imaging of the chest, abdomen and pelvis revealed no other sites of lymphoma.