A solution containing an attenuated, live culture preparation of the Bacillus Calmette Guerin (BCG) strain of Mycobacterium bovis with potential immunostimulating activity. Although the precise mechanism of action is unknown, upon intravesical administration, attenuated, live BCG bacteria in the solution come into direct contact with the bladder wall, inciting an antitumor granulomatous inflammatory reaction. Check for active clinical trialsusing this agent. or A type of cancer that forms in B cells (a type of immune system cell). B-cell lymphomas may be either indolent (slow-growing) or aggressive (fast-growing). Most B-cell lymphomas are non-Hodgkin lymphomas. There are many different types of B-cell non-Hodgkin lymphomas. These include Burkitt lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma, follicular lymphoma, and mantle cell lymphoma. Prognosis and treatment depend on type and stage of the cancer.