Background: Plasma cell leukemia (PCL) is a rare form of leukemia and plasma cell dyscrasia defined by the presence of greater than 2×109/L peripheral blood plasma cells or plasmacytosis accounting for more than 20 % of the differential white cell count. PCL can be divided into primary PCL (PCL) and secondary PCL (sPCL) following previously diagnosed multiple myeloma (MM). It has an aggressive clinical course. Aims: In this study, we aim to identify the main clinical and laboratory disease findings, treatment patterns, and evolution in patients with PCL in a Tunisian center. Methods: Our study is a review of all cases of PCL, diagnosed and treated between 2000 and 2021 at the hematology department of the hospital of Sfax, Tunisia. Results: Nine cases of PCL were identified: 8 primary PCL cases, and only one sPCL case. The mean age was 53 years [range 31-64], and there was a female predominance (6:3). Most presenting symptoms were bone pain noted in 5/9 patients, asthenia in 3/9 patients, and bleeding was noted in only one case. Physical examination revealed extramedullary involvement in 4 patients: 2 had splenomegaly, one had hepatomegaly and one had lymphadenopathy. None of our cases showed skin infiltrates. Standard radiologic surveys showed bone osteolysis in all 9 patients, generally in the skull, and MRI showed epidural space infiltration and spinal cord compression in 2 patients. Normocytic, normochromic anemia was noted in almost all patients with mean hemoglobin of 6.9 g/dl. Rouleaux formation and a leukoerythroblastic picture were evident on almost all the peripheral blood smears. The mean leukocytosis was 15.3x109/l [range 3.4-100] and consisted of 20% to 88% of plasma cells. Thrombocytopenia with platelets < 100x109/l occurred in 50% of patients. Immunophenotyping by flow cytometry was done only in 2 cases with difficult morphology and showed expression of CD38 and CD138. Hypercalcemia was noted in almost all patients (8/9), and renal failure was present in 4 cases. Immunofixation revealed an even distribution between IgG and IgA, and light chain in 3 cases. The frequency of the Kappa chain was higher. Serum albumin levels were low in all patients. For treatment, 4 patients received VTD (Bortezomib, Thalidomide, and Dexamethasone), 2 received VAD (Vincristine, Adriamycin, and Dexamethasone), 2 were on Thalidomide Dexamethasone, and one patient received Revlemid Dexamethasone. Only one patient of these four patients who received VTD underwent autologous stem cell transplant (ASCT) after attaining CR but relapsed after 2 years into multiple myeloma and is currently in PR receiving MPT. All other patients died of progressive and refractory disease. The median survival was 9 months with a duration ranging from 2 to 63 months. Summary/Conclusion: As reported internationally, our study showed that patients with PCL were younger than myeloma patients, and presented with more aggressive clinical and laboratory features at diagnosis especially more bone lesions than classically described, and a high frequency of hypercalcemia. Besides, it indicated that even after the use of novel drugs, response to treatment is poor and PCL still has a poor prognosis.

Abstract Abstract 4648 Objectives A central venous access is always necessary for the management of patients receiving myeloablative conditioning followed by allogeneic stem cell transplantation (SCT). Tunnelled, cuffed silastic catheters are the device of choice for these patients. To our knowledge, there are no prospective studies investigating the use of totally implantable central venous access ports (TIAP) in patients receiving myeloablative conditioning followed by allogeneic SCT. The aim of this prospective study was to investigate the usefulness of a new “high flow” single lumen port device in these patients. <>Methods: Between December 2007 and July 2009, patients with haematological malignancies received a TIAP prior to allogeneic SCT. All patients received the same type of port [silicone, 10 French, high flow rate (3100ml/h), Reference 40010, Laboratoires Perouse, Ivry le Temple, France]. All devices were inserted under local anesthesia through direct puncture of the right subclavian vein using the Seldinger technique. A chest X-ray was always obtained to document correct positioning. All infusions, including the graft itself and all blood drawings, were performed via the port. Port-related bloodstream infection was defined according to Infectious Disease Society of America guidelines. All patients were examined by ultrasonography in case of clinical signs of thrombosis and systematically after discharge. Results Forty six TIAP were placed in 46 patients [median age: 25 years (20-41 years); 20 female and 26 male], and remained in place for a cumulative duration of 9756 days in situ (range 30-560 days). No pneumothorax occurred. Port-related bloodstream infection occurred in 2 cases (candida parapsilosis and staphylococcus aureus) [2/46, 4.3% ; 0.2 event per 1000 days]. These ports were removed. No port-related thrombosis occurred. No port-related deaths were observed. In conclusion, the use of “high flow” totally implantable ports has resulted in a good option for long-term access to central veins and delivery of myeloablative conditioning followed by allogeneic SCT, in spite of severe neutropenia and increased risk of sepsis in this category of patients. Although multicentre randomized clinical trials are needed to define the optimal device in this clinical setting, the results of this prospective study support the wider use of TIAP in patients receiving myeloablative conditioning followed by allogeneic SCT. Disclosures: No relevant conflicts of interest to declare.