Hematological emergencies are critical medical conditions that require immediate attention due to their rapid progression and life-threatening nature. As various examples, hypercalcemia, often associated with cancers such as multiple myeloma, can lead to severe neurological and cardiac dysfunction. Hyperleukocytosis, common in acute myeloid leukemias, increases the risk of leukostasis and multiorgan failure. Sickle cell crisis, a common complication in sickle cell disease, results from vaso-occlusion, leading to acute pain and tissue ischemia. Tumor lysis syndrome, reported in cases of rapid destruction of cancer cells, causes electrolyte imbalances and acute kidney injury. Acute transfusion reactions, fundamental in hematological conditions, can range from mild allergic responses to severe hemolysis and shock, requiring prompt management. Disseminated intravascular coagulation, involving excessive coagulation and bleeding, is commonly triggered by hematological malignancies, common in the first phases of acute promyelocytic leukemia. Recently, in the era of bispecific antibodies and chimeric antigen receptor T cells, cytokine release syndrome is a manifestation that must be recognized and promptly treated. Understanding the pathophysiology, recognizing the clinical manifestations, and ensuring adequate diagnostic strategies and management approaches for each condition are central to early intervention in improving patient outcomes and reducing mortality.

Therapeutic phlebotomy remains a key intervention in the management of erythrocytosis and iron overload disorders, particularly polycythemia vera (PV) and hereditary hemochromatosis. Despite its historical origins as an ancient practice, venesection continues to be recommended in international guidelines for the reduction of hematocrit and iron burden, thereby mitigating thrombotic and organ-related complications. However, the evolving landscape of targeted pharmacologic therapies is reshaping the therapeutic paradigm. This review examines the current role of therapeutic phlebotomy, with a particular focus on PV, outlining its physiological rationale, clinical benefits, and well-documented limitations—including iron deficiency, procedural burden, and incomplete hematocrit control between sessions. Comparative insights are provided between phlebotomy and red cell apheresis, highlighting differences in efficacy, tolerability, and accessibility. The emergence of disease-modifying agents—such as interferons, JAK inhibitors, hepcidin mimetics, and epigenetic modulators like givinostat and bomedemstat—promises more sustained hematologic control with the potential to reduce or eliminate the need for repeated phlebotomies. While phlebotomy remains indispensable in early-stage or low-risk PV, its future utility will likely shift toward complementary or bridge therapy in the context of individualized, pharmacologically driven strategies, redefining the role of phlebotomy in the era of precision medicine.

Hodgkin Lymphoma (HL) is characterized by an inflammatory background in which the reactive myeloid cells may exert an immune-suppressive effect related to the progression of the disease. Immunoglobulin M is the first antibody isotype produced during an immune response, which also plays an immunoregulatory role. Therefore, we investigated if, as a surrogate of defective B cell function, it could have any clinical impact on prognosis. In this retrospective, observational, single–center study, we evaluated 212 newly diagnosed HL patients, including 132 advanced-stage. A 50 mg/dL level of IgM at baseline resulted in 84.1% sensitivity and 45.5% specificity for predicting a complete response in the whole cohort (area under curve (AUC) = 0.62, p = 0.013). In multivariate analysis, baseline IgM ≤ 50 mg/dL and the presence of a large nodal mass (<7 cm) were independent variables able to predict the clinical outcome, while, after two cycles of treatment, IgM ≤ 50 mg/dL at baseline and PET-2 status were independent predictors of PFS. The amount of IgM at diagnosis is a valuable prognostic factor much earlier than PET-2, and it can also provide information for PET-2-negative patients. This can help to identify different HL classes at risk of treatment failure at baseline.