A 21-year-old male patient presented with newly onset cervical lymph nodes in August 2020. PET-CT showed increased FDG uptake in bilateral cervical, mediastinal, paracaval, prevascular, right upper and lower paratracheal, subcarinal, right bronchopulmonary, right hilar and paraesophageal lymphadenopathies at the level of the malignancy (SUV max 3.8–11). He was diagnosed with ETP-ALL/LBL after evaluation of cervical lymph node biopsy at a local hospital. Bone marrow biopsy and flow cytometric analysis showed no increase in blasts. Bone marrow cytogenetics showed normal karyotype and revealed no numerical structural abnormalities. Next-generation sequencing and fluorescence in situ hybridization did not reveal any prognostically or therapeutically relevant variant. He had no central nervous system (CNS) involvement. First-line treatment was initiated with the HOELZER protocol, a CR was achieved and the entire protocol was completed. Allo-HSCT was not planned in CR1 at the local hospital, and no donor screening was performed. The last dose of maintenance treatment was administered in April 2023. He was admitted to our hospital for routine follow-up 3 months after completion of the HOELZER regimen. On presentation to our center, he complained of shortness of breath and fatigue. His laboratory values were normal. PET-CT was performed on suspicion of recurrence and showed a 9 cm pleural effusion, increased FDG uptake in the right pleura, right atrium and paraesophageal area at malignant level (SUV max 7.5–9.4). Second-line chemotherapy was started in our centre with the FLEND protocol (nelarabine, fludarabine and etoposide) + PEG-asparaginase. Intrathecal CNS prophylaxis was given. At the end of 1 cycle of FLEND + PEG-asparaginase, PET-CT showed progressive disease. Therefore, the BFM protocol was initiated as third-line chemotherapy. On the first day of the BFM protocol, the patient was diagnosed with catheter thrombosis and pulmonary thromboembolism, for which anticoagulant therapy was started. After the BFM induction protocol, progression was again detected on PET-CT. Subsequently, daratumumab (16 mg/kg every 2 weeks iv), venetoclax (400 mg d1-28), azacitidine (75 mg/kg d1-7 for 28 days) and dexamethasone (40 mg/weekly) protocol was initiated as a bridge to allo-HSCT. After explaining the unapproved nature of this treatment, the rationale for its use and the potential side effects of the drug, written informed consent was obtained. The regimen was well tolerated. Micafungin prophylaxis was also initiated to prevent any fungal infections. Grade 4 neutropenia occurred. Throughout the treatment period, erythrocyte and platelet replacement was not required. Neutropenic fever occurred once. No opportunistic infections were observed. After 1 cycle of treatment, the patient achieved a CR on PET-CT (Fig. 1). During all these treatments, the donor screening of the patient could not be carried out due to problems with the payment of the health insurance. Therefore, the second cycle of treatment was started to ensure the continuity of the response. Micafungin prophylaxis was also continued to prevent any fungal infections. A total of 2 treatment cycles were administered. However, grade 4 neutropenia occurred again in the 2nd cycle. On the 7th day of neutropenia, invasive pulmonary aspergillosis, haemophilius influenza type B and gram-negative sepsis developed. The patient was admitted to the intensive care unit and died due to ARDS.