Title of presented paper: Pain management of atypical infiltrations in the course of CLL -- a case report.

Introduction and aim. Chronic lymphocytic leukemia (CLL) is a hematological disease characterized by excessive aggregation of abnormal, monoclonal B-lymphocytes in bone marrow. This is the most frequent cause of leukemia in adult population. The leukemia cells may spread from the blood and bone marrow to other parts of the body, and most often they can be localized in lymph nodes, liver and spleen. Description of the case. A 64-year-old man with history of hypertension and permanent atrial fibrillation was admitted to the Hematolooncology Department with the diagnosis of CLL. The patient complained about pain in lumbar part of the spine. Patient was diagnosed with CLL 9 years earlier and treated with 6 cycles of Fludarabine-Cyclophosphamide-Rituximab (FCR). The patient has been under observation from that time. Although, there was a double increase of WBC in laboratory tests 2 months earlier, main reason for the admission was strong lumbar pain. The pain was initially treated with oxycodone, ketoprofen and different NSAIDs. The patient was ordered MRI, which showed extraspinal lesions proximal to iliac and cruciate bones with the sings of muscle infiltrations and other infiltrations in the lumbar part of the spine. After MRI, the patient was consulted with an anesthesiologist towards the change of pain management. The patient was advised to start therapy with tapentadol, paracetamol, dexketoprofen, pregabalin, and 5-day lignocaine intravenous drip infusion. Conclusion. Spine is a rare and uncommon localization of CLL infiltrations, and it is seldom described in literature. Patients with these infiltrations suffer from severe pain, so its management is crucial in order to decrease the patient's suffering. [ABSTRACT FROM AUTHOR]