[Utility of the bone marrow biopsy in the diagnosis of essential thrombocytemia].
Presse Med 2011;
40:e507-15. [PMID:
21737230 DOI:
10.1016/j.lpm.2011.04.014]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 03/03/2011] [Accepted: 04/04/2011] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION
The recent discovery of the Janus Kinase 2 (JAK2(V617F)) mutation, an indicator of clonal expansion, has widely modified the diagnostic work-up of myeloproliferative disorders. However, histopathologic criteria of the WHO classification, focused on megakaryocytes abnormalities, have taken a central role in the diagnosis of essential thrombocytemia (ET), particularly to distinguish it from the prefibrotic myelofibrosis (PMF) evolving to a clinic myelofibrosis unlike true ET. The aim of our study is to evaluate inter-observer reproducibility and prognostic implications of these pathological criteria comparing diagnoses with clinical and biological follow-up.
METHODS
Forty-four patients presenting with isolated thrombocytemia were retrospectively evaluated. All patients were initially diagnosed with ET based on the PVSG classification from 1997. The initial bone marrow biopsy specimens were re-evaluated using the Thiele pathological classification: true ET, prefibrotic myelofibrosis (PMF) and early myelofibrosis. Patients were followed for a median of 6 years.
RESULTS
Our population includes three patients with polycythemia vera and 41 patients with true ET. Based on clinical and biological follow-up, diagnoses were changed to idiopathic myelofibrosis in four of six patients with "early" myelofibrosis (66.7%), but in only one of 14 patients with PMF (7.15%). In contrast, the diagnosis of true ET was not changed in the 21 cases. Inter-observer reproducibility for pathological classification was 100%.
CONCLUSION
In this study, our diagnostic methodology based on the clinico-biological follow-up, which has not been evaluated in previous studies, calls into question the diagnostic value of the pathological criteria in PMF.
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