SDC1 and neoplasm: This tumour was initially described as a DLBCL with immunoblastic or large B cells and a phenotype resembling the terminally differentiated B cell, characterized by negative or weak expression of mature B-cell markers (CD20) and positivity for plasma cell-associated antigens (CD38, CD138).63 The tumours were mainly diagnosed in patients infected with the human immunodeficiency virus (HIV) and they presented commonly in the mucosa of the oral cavity.