[Diagnostic workup in front of an adult thrombocytosis]. / Conduite à tenir devant une thrombocytose de l'adulte.

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. More rarely, the diagnosis is oriented towards a clonal hematological pathology not limited to essential thrombocythemia. Currently, many biological tools, which have largely contributed to the recommendations of the latest WHO classification of chronic myeloid neoplasms, are available to classify these pathologies as precisely as possible, allowing optimal management.

[Diagnostic workup in front of an hypereosinophilia in 2020]. / Démarche diagnostique devant une hyperéosinophilie en 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. The potential etiologies are very numerous, mostly reactive and corticosensitive, much more rarely clonal in relation to a malignant hemopathy usually chronic and myeloid, sometimes sensitive to tyrosine kinase inhibitors.

[Lymphomas in immunocompromised patients]. / Lymphomes de l'immunodéprimé.

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. It is important to detect precisely these different categories of proliferation within each group of immunosuppression, to better individualize the prognosis and the management of patients.

[Diagnostic workup in front of an adult monocytosis]. / Conduite à tenir devant une monocytose de l'adulte.

The discovery of a monocytosis is a frequent phenomenon, requiring confirmation by reading under a microscope by an experimented biologist, to overcome usual cytological traps such as the presence of hairy cells, promonocytes or monoblasts. In the vast majority of cases the secondary origin is very easily found by the context and/or the presence of a biological inflammatory syndrome. More rarely the diagnosis is directed towards an eosinophilic pathology or an acute leukemia. In other cases, CMML, MPN or MDS with monocytosis may be highlighted. In the absence of any pathognomonic element and the presence of "borderline" forms the differential diagnosis between these 3 entities is not always straightforward, requiring, according to WHO, molecular investigations and elimination of any reactive cause of monocytosis. Although histological, immunohistochemical and phenotypic flow cytometric studies are not currently recommended by WHO, these investigations could be of interest in the evaluation of difficult cases.

[Monoclonal gammopathy of undetermined significance (MGUS): interpretative shades of analysis and sometimes serious clinical consequences]. / Point sur les GMSI : interprétation des examens complémentaires et complications cliniques.

The etiological assessment of a monoclonal gammopathy is currently standardized, the decisional algorithms allowing a sufficiently precise classification to consider the care, wait or therapeutic. The purpose of this review is to recall the difficulties concerning the interpretation of certain biological investigations and to point out the potential complications of monoclonal gammopathies labeled as "benign". The cooperation between clinicians and biologists is in all cases essential, allowing to propose on a case-by-case basis the best adapted explorations.

Diagnostic workup in front of an adult neutropenia.

Adult neutropenia, defined as a blood neutrophil count below 1.5 G/L, is a common condition. The most common cause of acute neutropenia is a drug-related reaction or an acute infectious disease. In chronic forms many etiologies are possible, sometimes poorly-defined, requiring precise explorations. The purpose of this article is to recall the required criteria for exploring neutropenia and to point out the algorithm of explorations in order to find the cause. Etiologies of acute and chronic forms are also detailed.

Central venous catheter-related infection due to Agrobacterium radiobacter: a report of 2 cases.

We report 2 cases of Agrobacterium radiobacter bacteremia in immunocompromised patients. Removal of the central venous catheter and administration of antimicrobial therapy led to favorable outcomes in both patients. Infections due to A. radiobacter are rare and usually occur in patients with predisposing factors.