Multiple myeloma (MM) is the second most common adult hematologic malignancy, and early intervention increases survival in asymptomatic high-risk patients. Imaging is crucial for the diagnosis and follow-up of MM, as the detection of bone and bone marrow lesions often dictates the decision to start treatment. Low-dose whole-body computed tomography (CT) is the modality of choice for the initial assessment, and dual-energy CT is a developing technique with the potential for detecting non-lytic marrow infiltration and evaluating the response to treatment. Magnetic resonance imaging (MRI) is more sensitive and specific than 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for the detection of small focal lesions and diffuse marrow infiltration. However, FDG-PET/CT is recommended as the modality of choice for follow-up. Recently, diffusion-weighted MRI has become a new technique for the quantitative assessment of disease burden and therapy response. Although not widespread, we address current proposals for structured reporting to promote standardization and diminish variations. This review provides an up-to-date overview of MM imaging, indications, advantages, limitations, and recommended reporting of each technique. We also cover the main differential diagnosis and pitfalls and discuss the ongoing controversies and future directions, such as PET-MRI and artificial intelligence.

This is the first case of acquired severe neutropenia in the context of COVID‐19 reported to date. This could illustrate another less frequent hematological disorder related to this novel viral infection.

Purpose: To compare the agreement between whole-body (WB) magnetic resonance (MR) imaging, ¹⁸F-FDG PET/CT, and skeletal survey (SS) in patients with multiple myeloma (MM) for diagnosis, initial staging, response evaluation, and early detection of complications. Methods: This is a retrospective cohort study including MM patients who were diagnosed, treated, and followed in 2 institutions. These patients were studied with SS, WB-MR, and/or ¹⁸F-FDG PET/CT. We studied bone lesions by anatomical locations and analyzed the concordance between SS and a tomographic technique (WB-MR or ¹⁸F-FDG PET/CT) and between both tomographic techniques (WB-MR and PET/CT). Results: Forty-four MM patients with a mean age of 62.6 years (range, 38–85 years) were included from January 2012 to February 2016. Whole-body MR and ¹⁸F-FDG PET/CT found more lesions than SS in every location except in the skull. Concordance between WB-MR and ¹⁸F-FDG PET/CT was either good or excellent in most of the locations and in plasmacytoma studies. However, WB-MR was better than ¹⁸F-FDG PET/CT in the study of complications (medullar compression and vascular necrosis). Conclusions: Our results suggest the study of MM patients should include WB-MR and/or ¹⁸F-FDG PET/CT, whereas SS is only useful for the skull. Whole-body MR and ¹⁸F-FDG PET/CT are complementary techniques, because both of them show good concordance in almost every location. It is still necessary to individualize the indication of each technique according to patient characteristics.

B-cell precursor acute lymphoblastic leukaemia (B-ALL) is a malignancy of lymphoid progenitor cells with altered genes including the Janus kinase (JAK) gene family. Among them, tyrosine kinase 2 (TYK2) is involved in signal transduction of cytokines such as interferon (IFN) α/β through IFN−α/β receptor alpha chain (IFNAR1). To search for disease-associated TYK2 variants, bone marrow samples from 62 B-ALL patients at diagnosis were analysed by next-generation sequencing. TYK2 variants were found in 16 patients (25.8%): one patient had a novel mutation at the four-point-one, ezrin, radixin, moesin (FERM) domain (S431G) and two patients had the rare variants rs150601734 or rs55882956 (R425H or R832W). To functionally characterise them, they were generated by direct mutagenesis, cloned in expression vectors, and transfected in TYK2-deficient cells. Under high-IFNα doses, the three variants were competent to phosphorylate STAT1/2. While R425H and R832W induced STAT1/2-target genes measured by qPCR, S431G behaved as the kinase-dead form of the protein. None of these variants phosphorylated STAT3 in in vitro kinase assays. Molecular dynamics simulation showed that TYK2/IFNAR1 interaction is not affected by these variants. Finally, qPCR analysis revealed diminished expression of TYK2 in B-ALL patients at diagnosis compared to that in healthy donors, further stressing the tumour immune surveillance role of TYK2.