[Diagnostic workup in front of an adult thrombocytosis].

During a blood test, the discovery of thrombocytosis is a frequent phenomenon with multiple origins. False thrombocytosis linked to analytical interferences is rare but must be eliminated before confirming the anomaly. The reaction origin, often very easily demonstrated by the context and/or the presence of a biological inflammatory syndrome, is the most frequent.

[Rare sideroblastic anemias: about 2 cases, review of the literature and reminder of the main etiologies].

Sideroblastic anemias in adults are often quickly labeled as myelodysplasias. We report two unfrequent observations of secondary acquired forms. The first one is a 15-year-old girl presented with severe cytopenias.

[Diagnostic workup in front of an hypereosinophilia in 2020].

The discovery of eosinophilia above 1.5 G/L should not be considered innocuous, requiring monitoring for etiology and possible secondary organ damage. Among these, cardiac localization is the most worrying, sometimes indolent, to be systematically sought by ultrasound and magnetic resonance.

[Lymphomas in immunocompromised patients].

Immunosuppression is a well known risk factor for the development of lymphoid pathologies. The classification of these neoplasias is becoming more precise and complex, some features being common to all immunocompromised patients, primarily the important influence of Epstein-Barr virus. Whatever the origin of the immunodepression, these lymphoid proliferations are very heterogeneous, constituting a wide range between polymorphic aspects and clearly lymphomatous morphologies indistinguishable from those observed in immunocompetent subjects.

[A new case of rare erythrocytosis due to EGLN1 mutation with review of the literature].

Introduction: The origin of polycythemia is often simple to detect. Sometimes it is necessary to look for hereditary forms, the decisive parameters being the dosage of erythropoietin and the measurement of the oxygen dissociation curve (P50). These rare diseases are related to high oxygen-affinity haemoglobins, abnormalities of the erythropoietin receptor or dysfunction of the HIF (hypoxia-inducible factor) pathway.