OBJECTIVE: To discuss and analyze the clinical and prognostic characteristics of rare prolymphocytic leukemia (PLL), in order to provide new references for the clinical diagnosis and treatment and basic research of PLL.
METHODS: The clinical data of 8 patients with PLL admitted to the Department of Hematology in Fujian Medical University Union Hospital from January 1, 2011 to May 31, 2023 were collected and retrospectively studied, and the clinical treatment and prognosis were analyzed. Meanwhile, the latest literature from PubMed was retrieved to systematically discuss the research progress in the diagnosis and treatment of PLL.
RESULTS: In this study, of the 8 patients with PLL, 6 were males and 2 were females; the ages ranged from 52 to 80 years, with a median age of 70.5 years. The immunophenotypes were divided into B-PLL (7 cases) and T-PLL (1 case). Morphological, flow cytometric, cytogenetic and molecular biological tests of bone marrow cells were performed in all patients. Among them, 1 case refused chemotherapy after diagnosis and died in a short time, the other 7 cases received standard chemotherapy. Among the 7 patients, one patient died of severe infection caused by myelosuppression after chemotherapy, one patient died within 3 months after chemotherapy; two patients died of progression at 4 and 7 months after chemotherapy. A total of 3 patients achieved complete remission (CR) after chemotherapy, and 1 patient underwent allogeneic hematopoietic stem cell transplantation without disease progression or recurrence.
CONCLUSIONS: PLL is a rare lymphoid malignancy with an extremely poor prognosis, which tends to occur in the elderly, and the clinical manifestations of PLL lack specificity. Chemotherapy combined with targeted drugs or epigenetic drugs may benefit PLL patients. Hematopoietic stem cell transplantation should be performed after CR is obtained to improve the prognosis to the greatest extent.

UNASSIGNED: B-cell prolymphocytic leukemia (B-PLL) is a rare mature B-cell tumor with an aggressive clinical course and poor prognosis. It is characterized by prominent splenomegaly and prolymphocytes exceeding 55% of the lymphoid cells in the blood. Purine analog-based chemo-immunotherapy is the first-line therapy for B-PLL. Owing to its rarity, there are few reports on the efficacy of bendamustine and rituximab (BR) regimen. Our study presents three cases of BR being effective in the treatment of B-PLL and provides experience for clinical treatment.
UNASSIGNED: This report describes the cases of three male patients (median age: 66 years old) who initially presented with abdominal discomfort. Physical examinations and imaging revealed splenomegaly, while a peripheral blood (PB) smear revealed a prolymphocyte count exceeding 70% of the lymphoid cells. Therefore, the three patients were diagnosed with B-PLL. Further molecular detection showed that they harbored P53 abnormalities (17p deletion/TP53 mutation) associated with resistance to conventional chemotherapies. In addition, one of the patients had a highly complex karyotype and multiple gene mutations. All patients underwent four cycles of BR, and two of them received two further cycles of rituximab monotherapy. Ultimately, the patients achieved a complete response (CR) that lasted for 25, 33, and 34 months, respectively, with a median follow-up time of 34 months. The adverse events of the BR mainly included a grade 3 haematological toxicities. Also, the treatment was well-tolerated.
UNASSIGNED: This case series suggests that BR regimen is promising for bringing deep remission to patients with B-PLL. Prospective trials are still required for further elucidation.

T cell prolymphocytic leukemia (T-PLL) is a rare, aggressive malignancy with limited treatment options and poor long-term survival. Previous studies of allogeneic hematopoietic cell transplantation (alloHCT) for T-PLL are limited by small numbers, and descriptions of patient and transplantation characteristics and outcomes after alloHCT are sparse. In this study, we evaluated outcomes of alloHCT in patients with T-PLL and attempted to identify predictors of post-transplantation relapse and survival. We conducted an analysis of data using the Center for International Blood and Marrow Transplant Research database on 266 patients with T-PLL who underwent alloHCT between 2008 and 2018. The 4-year rates of overall survival (OS), disease-free survival (DFS), relapse, and treatment-related mortality (TRM) were 30.0% (95% confidence interval [CI], 23.8% to 36.5%), 25.7% (95% CI, 20% to 32%), 41.9% (95% CI, 35.5% to 48.4%), and 32.4% (95% CI, 26.4% to 38.6%), respectively. In multivariable analyses, 3 variables were associated with inferior OS: receipt of a myeloablative conditioning (MAC) regimen (hazard ratio [HR], 2.18; P < .0001), age >60 years (HR, 1.61; P = .0053), and suboptimal performance status, defined by Karnofsky Performance Status (KPS) <90 (HR, 1.53; P = .0073). Receipt of an MAC regimen also was associated with increased TRM (HR, 3.31; P < .0001), an elevated cumulative incidence of grade II-IV acute graft-versus-host disease (HR, 2.94; P = .0011), and inferior DFS (HR, 1.86; P = .0004). Conditioning intensity was not associated with relapse; however, stable disease/progression was correlated with increased risk of relapse (HR, 2.13; P = .0072). Both in vivo T cell depletion (TCD) as part of conditioning and KPS <90 were associated with worse TRM and inferior DFS. Receipt of total body irradiation had no significant effect on OS, DFS, or TRM. Our data show that reduced-intensity conditioning without in vivo TCD (ie, without antithymocyte globulin or alemtuzumab) before alloHCT was associated with long-term DFS in patients with T-PLL who were age ≤60 years or who had a KPS >90 or chemosensitive disease.

B-cell prolymphocytic leukemia (B-PLL) is a rare leukemia characterized by rapidly increasing leukocytosis with splenomegaly and lymphadenopathy. Treatment strategies are largely based on studies of chronic lymphocytic leukemia (CLL). Antibodies against the cell surface protein CD20 are considered to be first-line therapy. A 76-year-old male with known CLL presented 2 weeks after starting chemoimmunotherapy for newly refractory CLL after failing ibrutinib therapy. White blood cell count was elevated at 226.7 × 103/µL. Fluorescent in situ hybridization analysis of a bone marrow specimen showed new development of complex cytogenetics. Flow cytometry revealed B cells appearing slightly dimmer on CD45 and brighter on CD20 compared with typical B-CLL suggestive of less mature lymphocyte forms. The patient was diagnosed with B-PLL and started on obinutuzumab and venetoclax with rapid normalization of white blood cells. This case recapitulates the challenges in diagnosing and treating B-PLL. Ibrutinib resistance is a growing area of study with several proposed mechanisms of acquired resistance. The pathogenesis of B-PLL is not completely understood, although mutations in MYC are presumed to play a role.

BACKGROUND: We describe a case of alemtuzumab (Campath®) hypersensitivity requiring desensitization within the medical intensive care unit (MICU) in a patient with T-cell prolymphocytic leukemia.
METHODS: We adopted a desensitization protocol from Gutierrez-Fernandez et al., which included three aliquots (0.15 mg intravenously (IV), 1.5 mg IV, and 28.5 mg IV) given approximately 1 h apart on day 1 followed by a full 30 mg dose IV on day 3. Unlike prior attempts to administer alemtuzumab to this patient, she tolerated the medication well and did not require any rescue medications.
UNASSIGNED: Successful plan development required a significant amount of strategic communication between hematology/oncology and MICU-related physicians, pharmacists, and nurses to ensure a safe and effective desensitization. The first step of planning required creation of a desensitization order set with directions for medication preparation and administration, premedications, and available medications in the event of an adverse reaction or anaphylaxis. Anaphylactoid-related medications were prepared at bedside and ready for administration prior to beginning the desensitization. Alemtuzumab was compounded in a chemotherapy-certified hood and verified by at least two chemotherapy-certified pharmacists. Foreword planning was also necessary to ensure multiple people were available or present at bedside for the desensitization, including a chemotherapy-certified nurse, a second chemotherapy-certified nurse for verification, a critical care-certified pharmacist, a pulmonary/critical care attending physician, and hematology attending physician.
CONCLUSIONS: This case exemplifies the importance of clear and coordinated communication between different healthcare fields to safely and effectively complete extensive protocols such as desensitization strategies.

BACKGROUND: Post-transplant lymphoproliferative disorder is a serious disorder which occurs post hematopoietic stem cell transplant or solid organ transplantation. T-prolymphocytic leukemia is a T cell type monomorphic post-transplant lymphoproliferative disorder which accounts for only 2% of all mature lymphocytic leukemias in adults over the age of 30.
METHODS: A 59-year-old man of Chinese ethnicity presented to our hematology unit with headache, lethargy, and exertional dyspnea for the past 1 month. He underwent an uneventful cadaveric renal transplant 20 years ago for chronic glomerulonephritis-induced end-stage renal disease. He had been on long-term immunosuppressants since then consisting of orally administered prednisolone 10 mg daily and orally administered cyclosporine A 50 mg twice daily. On examination, he was pale with a palpable liver and spleen. He had a functioning renal graft. Marrow flow cytometry confirmed T-prolymphocytic leukemia with lymphocytes expressing CD2, CD3, CD7, CD52, and TCL-1. His human T-cell lymphotropic virus and Epstein-Barr virus serology and deoxyribonucleic acid (DNA) were negative. He was treated with one cycle of cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy to which he failed to respond. In view of his renal allograft, he was not suitable for alemtuzumab due to the risk of nephrotoxicity. He was given orally administered venetoclax but he died on day 17 due to severe auto tumor lysis syndrome.
CONCLUSIONS: The place of immunophenotyping in the diagnosis and treatment of this disorder is of significant importance. More research needs to be carried out to further comprehend the pathophysiology and treatment modalities for this disorder.

Although rare cases of prolymphocytic transformation from splenic B-cell lymphomas and follicular lymphoma have been reported, prolymphocytic transformation from lymphoplasmacytic lymphoma has not been previously reported. We report a case of 76-year-old-male patient with a history of Waldenström macroglobulinemia diagnosed in 2010 and treated with infusion chemotherapy. He was in clinical remission for 5 years. In 2016, he presented with diffuse lymphadenopathy, and a head and neck lymph node biopsy showed lymphoplasmacytic lymphoma. MYD88 mutation was detected by polymerase chain reaction. A subsequent bone marrow biopsy showed B-cell lymphoma with increased prolymphocytes. Peripheral blood showed numerous circulating prolymphocytes. MYD88 was detected by polymerase chain reaction in the bone marrow. Cerebrospinal fluid was positive for lymphoma cells with prolymphocytic morphology. An IgM κ paraprotein was noted by immunofixation performed on the patient\'s serum, urine, and cerebrospinal fluid. The patient was resistant to chemotherapy, developed multiorgan failure, and died shortly thereafter.

Background: T-cell prolymphocytic leukemia (T-PLL) is a rare lymphoid malignancy with dismal prognosis. Most patients have increased lymphocyte count (>1,00,000/dL) and widespread disease at presentation. Despite high response rate seen with alemtuzumab, the disease relapse is inevitable. Materials andMethods: This was a retrospective observational study done at a tertiary cancer center in South India. All patients diagnosed with T-PLL from August 2010 to July 2015 were studied for the clinical characteristics, pathological findings and treatment outcomes. Results: Seven patients were diagnosed as T-PLL over a period of 5 years. The median age at diagnosis was 51 years. In the present series, 6 patients (86%) had splenomegaly and 3 had hepatomegaly (43%). Generalized lymphadenopathy was seen in 4 (57%) patients at presentation. Skin lesions were seen in 5 (71%) patients, whereas pleural effusion was seen in only one patient (14%). All had elevated total leukocyte count, with more than 1, 00,000/dL in 4 patients. The median survival was 5 months with different chemotherapy (CT) regimens (5 patients treated with CT and 2 received best supportive care). Conclusion: T-PLL is a rare disease with no definite treatment guidelines. At present, the best outcomes are achieved if treatment with alemtuzumab is followed by stem cell transplant, but the disease invariably relapses. Countries where affordability remains a big challenge, the best approach needs to be defined beyond the monoclonal antibodies and transplant.

BACKGROUND: T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive disease. In this study, we report our experience from 119 patients with T-PLL.
METHODS: We reviewed the clinico-pathologic records of 119 consecutive patients with T-PLL, who presented to our institution between 1990 and 2016.
RESULTS: One hundred and nineteen patients with T-PLL were analysed. Complex karyotype and aberrations in chromosome 14 were seen in 65% and 52% patients, respectively. Seventy-five patients (63%) were previously untreated and 43 (37%) were initially treated outside our institution. Sixty-three previously untreated patients (84%) received frontline therapies. Overall, 95 patients (80%) have died. Median overall survival (OS) from diagnosis was 19 months [95% confidence interval (CI) 16-26 months]. Using recursive partitioning (RP), we found that patients with hemoglobin < 9.3 g/dl, lactate dehydrogenase (LDH) ≥ 1668 IU/l, white blood cell  ≥ 208 K/l and β2M ≥ 8 mg/l had significantly inferior OS and patients with hemoglobin < 9.3 g/dl had inferior progression-free survival (PFS). In multivariate analysis, we identified that presence of pleural effusion [hazard ratio (HR) 2.08 (95% CI 1.11-3.9); P = 0.02], high LDH (≥ 1668 IU/l) [HR 2.5 (95% CI 1.20-4.24); P < 0.001)], and low hemoglobin (< 9.3 g/dl) [HR 0.33 (95% CI 0.14-0.75); P = 0.008] were associated with shorter OS. Fifty-five previously untreated patients received treatment with an alemtuzumab-based regimen (42 monotherapy and 13 combination with pentostatin). Overall response rate, complete remission rate (CR) for single-agent alemtuzumab and alemtuzumab combined with pentostatin were 83%, 66% and 82%, 73% respectively. In patients who achieved initial CR, stem cell transplantation was not associated with longer PFS and OS.
CONCLUSIONS: Outcomes in T-PLL remain poor. Multicenter collaborative effort is required to conduct prospective studies.

OBJECTIVE: We aimed to produce a comprehensive update on clinical and biological data regarding two rare lymphoid neoplasms, B and T prolymphocytic leukemias, and assess therapeutic management in the light of new molecular insights and the advent of targeted therapies.
RESULTS: B cell prolymphocytic leukemia (B-PLL) diagnosis remains challenging in the absence of clear immunophenotypic or cytogenetic signature and overlap with mantle cell lymphoma. New molecular defects have been identified in T cell prolymphocytic leukemia (T-PLL), especially in the JAK STAT pathway. Like in chronic lymphocytic leukemia (CLL), B-PLL treatment depends on the presence of TP53 dysfunction. In T-PLL, alemtuzumab still remains the standard of care. Allogeneic transplantation is the only curable option. Thanks to reduced intensity conditioning regimens, it has become accessible to a larger number of patients. PLL prognosis remains poor with conventional therapies. However, great advances in the understanding of both T- and B-PLL pathogenesis lead to promising new therapeutic agents.