This pattern of malignant lymphoma is diffuse and no lymphoid follicles are identified in this lymph node. Note that the normal architecture of the lymph node is obliterated. The lymph node is replaced by an infiltrate of small (mature-appearing) neoplastic lymphocytes, and the infiltrate extends through the capsule of the lymph node and into the surrounding fat. These cells will mark as B lymphocytes. The diagnosis is: small lymphocytic lymphoma (SLL). This is the tissue equivalent of chronic lymphocytic leukemia (CLL), and both often occur together (CLL/SLL). Though both are indolent, they are widespread and difficult to treat.