Spinal cord lymphoma
The patient went on to have a biopsy.
The sections show a densely cellular malignant infiltrate, forming sheets. Many of the tumor cells have plasmacytoid appearance. Mature plasma cells are seen. Other cells are medium to large in size and they are more atypical and pleomorphic with enlarged clefted and hyperchromatic nuclei, focal conspicuous nucleoli, clumped chromatin, perinuclear hofs and some eosinophilic cytoplasm. There are no granulomas. The atypical cells show kappa light chain restriction, confirming malignancy. Scattered large cells are CD20 positive and they have infiltrative pattern, most probably representing malignant B-cells. Some cells are also CD138 and EMA positive. Most of the cells in this biopsy are bcl-2, CD79a and MUM1 positive. The Ki-67 index is about 20%. PAX-5, CD10, CD30, CD56 and EBER-CISH are negative.
Comment: Given the presence of CD20 positivity and past history of lymphoma, this tumor is interpreted as diffuse large B-cell lymphoma. The plasmacytoid features are very prominent which can be seen in DLBCL.
DIAGNOSIS: Diffuse large B-cell lymphoma with prominent plasmacytoid features.