Abstract
Primary bone lymphomas are unusual, and accounts for 2% among all lymphomas. Primary sacral lymphomas are still rarer with only 12 cases reported till date. They predominantly affect elderly males, showing occasional spinal epidural space involvement. We report a case of 49-year-old male complaining of low backache and radicular pain for 2 months, followed by the development of parasthesia and bladder and bowel involvement. Lumbosacral spine magnetic resonance imaging revealed an expansile lytic lesion of approximately 6.5 cm with enhanced soft-tissue component extending to neural foramina compressing the spinal cord. Biopsy showed non-Hodgkin's lymphoma showing CD20, B-cell lymphoma (BCL) 6, BCL2, Multiple myeloma (MM) antigen 1 (MUM 1), and Cellular myelocytomatosis oncogene (C-Myc) positivity with CD10 negativity. Thus, the diagnosis of diffuse large B-cell lymphoma (DLBL)-activated B-cell type was rendered. Thirty cases of CD10-negative DLBL with Myc translocation in bone have been found which occur predominantly in Asians. Sacral primary DLBL with Myc translocation is extremely rare, only two cases are reported till date to the best of our knowledge. Because of its rarity, the prognosis and treatment of this entity are still not clear.