Essential thrombocythemias. Clinical evolutionary and biological data

Abstract

This retrospective study reviewed 94 patients, aged 6 to 90 years, with thrombocythemia. The women/men ratio was 1.76. At onset or, less commonly, during the course of the disease, 45% of the patients presented hemorrhagic manifestations, 29% thrombotic complications, and only 14% the association of hemorrhage and thrombosis. The average platelet count was 1200 X 10(9)/1, with no difference according to sex or age. Platelet hypoaggregation was seen in practically all the cases (94%), although myelofibrosis was less frequent (54%). The frequency of hemorrhages increased when the platelet count was above 1000 X 10(9)/1 (P less than 0.01), but the occurrence of thrombosis was correlated neither with platelet count nor with thrombopathy. Survival time was lengthy: 80% of survival (standard error 6%) was observed at 100 months. Transformation to acute leukemia was observed in five patients. Because the disease course is most often prolonged, therapeutic measures must be conservative: anti-aggregating drugs in small doses, and chemotherapy beginning with nonalkylating agents.

Follow‐up examinations including sequential bone marrow biopsies in essential thrombocythemia (ET): A retrospective clinicopathological study of 120 patients

“…The obvious difficulty to distinguish ET from initial IMF is further documented by the enormous range of frequency concerning the presence of reticulin fibrosis in larger series of patients. A number of relevant evaluations reported an incidence of up to 54% [15][16][17]23]. This result fits well with our findings that by following the PVSG criteria [3] many patients with (initial-early) IMF and accompanying thrombocytosis were regarded as ET [30].…”

“…These data oppose the data of other reports on the incidence of fibrotic changes in those patients at presentation ranging up to 54% [15][16][17]. Moreover, in follow-up examinations a number of cases with a significant increase in the fiber content complicated by blastic crisis were described [14,15,[18][19][20][21][22]. Regarding these strikingly different frequencies of reported myelofibrosis in ET, it is tempting to speculate about the heterogeneity of disease features or selection of patients.…”

“…However, a critical revision of these diagnostic guidelines that until now have been generally accepted in leading clinical trials [15,16,21] reveals that histopathology is only marginally considered. This shortcoming regards in particular the failing description of megakaryocyte morphology which has been supplemented by the new WHO classification [12].…”

“…In these initial to early stages of ET, representative pretreatment BM biopsies are essential to establish the clear-cut differentiation from reactive thrombocytosis [6,7,34]. This postulate concerns in particular patients presenting with complications like hemorrhage, thrombosis [9,11,15,16,35,36], neurologic manifestations [37], and even erythromelalgia [38]. As has been demonstrated in this observational clinicopathological study, repeatedly performed BM trephines lend further support to the fact that only a fraction (about 35%) of the total series was compatible with (true) ET.…”

“…In this context it is noteworthy that in a large series of patients with ET, derived from a reference center, only 3% showed a minimal to moderate reticulin fibrosis at diagnosis and in less than 10% development of myelofibrosis occurred during the course of disease [13,14]. These data oppose the data of other reports on the incidence of fibrotic changes in those patients at presentation ranging up to 54% [15][16][17]. Moreover, in follow-up examinations a number of cases with a significant increase in the fiber content complicated by blastic crisis were described [14,15,[18][19][20][21][22].…”