Hypereosinophilia: a diagnostic challenge

Hypereosinophilia encompasses a broad differential diagnosis of atopy/allergic reactions, drug reactions, parasitic infections and paraneoplastic syndromes. Although mostly of limited clinical significance, hypereosinophilia can also be related to hematological malignancies. One has to be aware of the potential for secondary organ damage for example, in the case of hypereosinophilic syndrome. We present three cases with different underlying mechanisms of hypereosinophilia with a brief overview of causes, diagnostic work-up and treatment options.

The achievements of the EORTC Lymphoma Group. European Organisation for Research and Treatment of Cancer

From 1964 onwards, the EORTC Lymphoma Group has conducted seven consecutive randomised phase 3 trials on early stage Hodgkin's lymphoma aiming at increasing efficacy, while decreasing short- and long-term toxicity. Staging laparotomy is definitely abandoned and replaced by identification of prognostic subgroups based on pretreatment clinical characteristics. Event-free and overall survival significantly improved from about 50 and then 70%, in the early years, to over 80 and then 90% more recently. Radiotherapy fields have become more restricted, whereas chemotherapy has become standard. Longitudinal quality-of-life assessment has become an integral part of our studies. In advanced stages, overall outcome has improved as well with 6-year survival rates of over 80%. In aggressive types of NHL, the second generation chemotherapy schedule CHVmP-BV was superior to CHVmP. We could not show any advantage for intensification of upfront treatment with autologous stem cell transplantation.

A search for novel tumour suppressor genes for adult acute leukaemia by allelotyping at sub-telomeric chromosomal regions

A search was initiated towards the localization of novel mutated tumour suppressor genes that may be involved in adult leukaemia. For this purpose, we measured the occurrence of loss of heterozygosity (LOH) in nine patients with acute B-lineage leukaemia (ALL) and one with undifferentiated leukaemia (AUL). Eight leukaemias exhibited a diploid karyotype. For each patient, PCR products of 130 polymorphic microsatellite markers, located in subtelomeric areas of every autosomal chromosome arm were analysed to visualize LOH events resulting from reduplication of a single mutated chromosome or from mitotic recombination. These kinds of LOH events contribute most to LOH in model systems but cannot be detected by classical cytogenetic techniques. By comparing allelic PCR products in tumour cells with those in normal cells, LOH was found in tumour cells of one ALL patient at 9p which harbours the known p16INK4A tumour suppressor gene. In the AUL patient, however, LOH was detected at the telomeres of 4q and 21q, suggesting that these sites may contain novel tumour suppressor genes specifically involved in this form of leukaemia. In the DNA of tumour cells from eight out of 10 patients no LOH was detected. This is in contrast with the general assumption that LOH is a frequent phenomenon in ALL. However, some markers at telomeric regions of chromosomes were already homozygous in the control T-cells of several patients. For instance, we found in the DNA of control cells from one patient five consecutive microsatellites on 9p up to 9p43 which were homozygous and in three other patients homozygosity was observed in band 8q24, which includes the MYC gene. These observations indicate that LOH events already are present in non-cancerous putative stem cells and that mitotic recombination may be a very early event in leukaemogenesis.