Biopsy of the nodal mass surrounding the celiac trunk was performed.

HISTOLOGY:

The lymph node core biopsy shows complete architectural effacement. There is a proliferation of atypical lymphoid cells, forming diffuse sheets. No follicular structures are seen. The atypical lymphocytes are large in size. They have enlarged clefted and hyperchromatic nuclei, prominent nucleoli and scanty cytoplasm. The tumor cells are CD20, bcl-2, bcl-6 and MUM1 positive. The Ki-67 index is about 95%. c-Myc immunostain stains about 70% of the cells. They are CD3, CD5, CD10 and EBER-CISH negative. The features are those of diffuse large B-cell lymphoma, with activated B-cell-like phenotype. Presence of bcl-2 and about 70% of the cells being c-Myc immunostain positive is suggestive of 'double hit' lymphoma.

DIAGNOSIS:  Diffuse large B-cell lymphoma.