Eleven years ago, a 64-year-old Caucasian man had LNH Follicular 3a, IV A stage, FLIPI 2 as a prognostic index of follicular lymphoma. He received 8 cycles of RCHOP followed by rituximab maintenance, with complete remission. Due to a systemic recurrence, a new treatment schedule (RCOMP, 6 cycles) was introduced with partial remission persisting during a long-term maintenance treatment with rituximab. Three years ago, LNH Follicular 3a progressed into GC type diffuse large B-cell lymphomas (DLBCL); 6 cycles of rituximab and bendamustine were followed by R-ICE and R OXALI DHAP treatments without beneficial effect. Due to the worse general condition (ECOG 3–4), the patient was treated with pixantrone (6 cycles) until July 10, 2019, with a partial response. On Jan 13, 2020, an extreme compassioned treatment with venetoclax alone was started; this drug was well tolerated and provided a satisfactory clinical and laboratory improvement. In June 2020, however, he developed bone marrow toxicity and septic fever. Nasal and pharyngeal secretions were SARS-CoV-2 RNA negative. Blood cultures for mycotic agents and Gram-positive, Gram-negative, and anaerobic bacteria were negative, but few days later, the patients died of sepsis due to unidentified agents. The use of venetoclax as a single drug to treat DLBCL BCL2 patients deserves further investigation.