Immunophenotypic characterisation of acute leukaemia after polycythemia vera

Acute lymphoid leukemia following polycythemia vera

The tendency to evolve into acute leukemia is a well-known characteristic of polycythemia vera (PV), which is shared with the remaining chronic myeloproliferative disorders and increases after the administration of cytotoxic agents. Acute transformation is usually of myeloid phenotype, whereas acute lymphoid leukemia (ALL) following PV is seldom observed. A 63-year-old woman is described who developed ALL at 6 years from the initial diagnosis of PV, for which she had received radioactive phosphorus and hydroxyurea. The ALL was of B-cell type, corresponding to the L-3 subtype of the FAB classification. Despite the administration of combination chemotherapy the patient died shortly after the diagnosis of acute leukemia. The present case adds to seven previously described patients with the above association, all of whom had received cytotoxic therapy for PV. Median interval from PV to ALL diagnosis was 10 years, and there was a predominance of the B-cell phenotype. The prognosis was poor since all but one of the patients had a short survival after ALL diagnosis. The possible etiological and pathogenetic link between PV and the subsequent ALL is discussed.

Treatment of Polycythemia Vera: The Use of Hydroxyurea and Pipobroman in 292 Patients Under the Age of 65 Years

Nonradiomimetic drugs, hydroxyurea (HU) and pipobroman (Pi), were administred to relatively young subjects with polycythemia vera (PV) in an attempt to decrease the leukemogenic risk observed in patients treated with 32P. Clinical safety, hematological efficacy, risk of carcinoma or leukemia, and frequency of progression to myelofibrosis have not yet been defined in long-term studies, and no comparative studies of HU and Pi have been conducted. Since 1980, 292 patients with PV diagnosed before the age of 65 years were randomized to receive treatment with HU (25 mg/kg/d, followed by low-dose maintenance) or Pi (1.2 mg/kg/d, followed by low-dose maintenance). Patients were followed until death or until May 1997. Drug tolerance was often poor; leg ulcers and buccal aphthous ulcers (with HU) and gastric pain and diarrhea (with Pi) sometimes required treatment change, mainly in the HU arm. Hematological stability, especially in terms of platelet count, was very often insufficient with HU (45% of cases), but the risk of thrombo-embolic event was similar in both arms. Actuarial survival was similar in the two arms and shorter than that of the reference population. The risk of leukemia was approximately 10% at the 13th year, with no significant difference between the two arms. The risk of carcinoma (when excluding the skin cancers) was similar in both groups. There was a high risk of progression to myelofibrosis in the patients treated by HU, which was significantly higher than with Pi.

Classification and staging of Ph-negative myeloproliferative disorders by histopathology from bone marrow biopsies

The present study illustrates characteristic features of histopathology in the 3 non-leukemic, Ph-negative groups of chronic myeloproliferative diseases (CMPD). Attention is paid to the final outcome of CMPD, especially its transformation into acute leukemias and the occurrence of myelofibrosis from bone marrow biopsies (BMB) in a total of 1,716 CMPD patients. Essential thrombocythemia (ET), polycythemia vera (P. vera), and chronic megakaryocytic granulocytic myelosis (CMGM) can readily be distinguished by histopathology from BMB in the great majority of patients without regarding laboratory data, leaving a compartment of about 12% unclassifiable cases. Histologic patterns of staging are the increase in number and pleomorphism of megakaryocytes (MK), increase in number and density of reticulin fibers and collagen fibrosis, and excess of blasts. These 3 criteria are each graded from 0 to 3 in every biopsy. From these, a staging results by means of the histology of BMB in each of the Ph-negative CMPD. This staging provides a classification by defined criteria which permits comparative studies, the possibility of monitoring the individual patients by follow-up histology, and offers a baseline for reliable evaluation of results from therapy protocols.

Polycythemia vera

OBJECTIVES

To review the proliferative nature of polycythemia vera (PV), clinical features, laboratory findings, treatment options and controversies, and nursing management.

DATA SOURCES

Textbook chapters and review articles that pertain to polycythemia vera.

CONCLUSIONS

Polycythemia vera is a chronic myeloproliferative disorder that can evolve into acute leukemia. Treatment options include phlebotomy, myelosuppressive agents, interferon, and platelet inhibitors.

IMPLICATIONS FOR NURSING PRACTICE

Nursing management of the patient with PV is challenging because of the evolving nature of the disease and treatment-related complications. Close monitoring and compliance with the treatment plan is necessary.

Anaplastic B-cell (Ki-1) lymphoma developing in a patient with polycythemia vera

The association of lymphoproliferative disorders and polycythemia vera (PV) is extremely rare. Here we report a patient with PV who developed anaplastic B-cell (Ki-1) non-Hodgkin's lymphoma (NHL). The rare occurrence of lymphoproliferative disorder in the course of PV, may indicate that in a minority of patients, clonal expansion of an abnormal pluripotent haemopoetic stem cell could be responsible for both the PV and the NHL.

Flow cytometry in the diagnosis of cancer

Flow cytometry has rapidly expanded from basic research to clinical laboratories mainly due to its unique characteristics regarding cell analysis. Among the clinical uses of flow cytometry cancer represents one of the most relevant. Several applications of flow cytometry can currently be applied to the study of cancer, including the detection of tumour cell DNA aneuploidy, the analysis of tumour cell proliferation and the immunophenotyping of leukemias. Although standardized flow cytometry protocols for these applications are scanty, the clinical value has been clearly established. The presence of DNA aneuploidy and a high proportion of S-phase tumour cells have been associated with tumour malignancy and a poor prognosis. The immunophenotype of leukaemia is of great help both for the diagnosis and classification of chronic lymphoproliferative disorders and acute leukaemias, especially in acute lymphoblastic leukemia cases and the M0, M3-variant, M6 and M7 acute myeloblastic leukaemia subtypes. In addition, it allows the identification of relatively rare leukemia cases such as the biphenotypic and the Nk-cell lineage leukemias. The development of flow cytometry is continuously bringing new applications into the clinical laboratory in the area of cancer diagnosis.

Polycythaemia rubra vera transforming to acute lymphoblastic leukaemia with a common immunophenotype

Lymphoblastic transformation of polycythaemia rubra vera is an extremely rare phenomenon. A case of a 76 year old man with polycythaemia rubra vera who developed acute lymphoblastic leukaemia (ALL) 16 years after his initial diagnosis is reported. Membrane markers showed a CD10 positive (common ALL) immunophenotype. To our knowledge this association has not been previously recorded. The rare occurrence of ALL in polycythaemia rubra vera may indicate that in a minority of patients clonal expansion of an abnormal pluripotent haemopoietic stem cell is responsible for the polycythaemia rubra vera disease phenotype.