Neoplastic plasma cells (PCs) proliferation at anatomic sites dislocated from the bone marrow (BM) or their contiguous growth from osseous lesions that disrupt the cortical bone is termed extramedullary multiple myeloma (EMD). EMD still remains challenging from a therapeutic and biological perspective. Pathogenesis has not been completely clarified, and it is generally associated with high-risk cytogenetics (HRCAs). In order to emphasize the clinical and biochemical complexity of this disease, we have decided to describe the case of a patient affected by relapsed-refractory (RR) EMD, which presented as para-osseous plasmacytoma with a bi-phenotypical immunoglobulin (Ig) component and lately relapsed as soft-tissue plasmacytoma with a total immunophenotype switch. We have also hypothesized a correlation between Ig patterns and prognosis and suggested the possible inclusion of these biochemical features in the general risk assessment.

Background: Waldenström macroglobulinemia (WM) is a rare and indolent B-cell lymphoproliferative disorder with greater incidence in elderly patients where a precise algorithm of initial therapy is still not clear. Immunochemotherapy regimen consisting of dexamethasone, rituximab, and oral cyclophosphamide (DRC) is considered a suitable first-line treatment because of its safety, efficacy, and manageability.Patients and methods: We retrospectively describe the results of 36 consecutive treatment-naïve patients with WM who were treated from June 2013 until June 2021 with the DRC regimen every 4 weeks instead of 3 weeks, for six cycles. The median age was 69 years (range, 42–85 years), with one-third being older than 75 years. Most patients had features of advanced disease, with nearly 60% being high risk. Median IgM level prior to treatment initiation was 2.9 g/dL.Results: Overall response rate was 80% after a median time of two cycles, with 67% of patients achieving at least partial response. After a median follow-up of 59 months, the median overall survival (OS) was not reached and the median time to next treatment (TTNT) was 48 months (95% CI 25–87 months). Approximately 70% of the evaluable study population had a 3-year survival without additional treatment, while 75% had a 3-year OS rate. The treatment was well-tolerated with only two patients (6%) recorded to have grade 3 pneumonia and no grade 3 hematological toxicity maybe due to the regular use of growth factors for red and white blood cells. Baseline albumin level and achievement of at least minimal or partial response had a significant impact on TTNT, while baseline hemoglobin and IgA level affected outcome in terms of OS (p < 0.05).Conclusion: This is the first real-life experience describing the use of the DRC regimen in treatment-naive patients with WM with administration of therapy every 4 weeks instead of 3 weeks showing apparent comparable efficacy, along with good tolerability and safety, especially in terms of hematological toxicity, independently from comorbidity burden.

Acute promyelocytic leukemia is a rare form of acute myeloid leukemia in which immature promyelocytes abnormally proliferate in the bone marrow. In most cases, the disease is characterised by the translocation t(15;17) (q24;q21), which causes the formation of PML::RARA, an oncogenic fusion protein responsible for blocking myeloid differentiation and survival advantage. Here, we present a case of acute promyelocytic leukemia with two unusual features: basophilic differentiation and a three-way translocation involving chromosomes 12, 15 and 17. In the few cases reported, basophilic differentiation was associated with a poor prognosis. In contrast, our patient responded promptly to the standard treatment with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) and obtained complete remission. To our knowledge, this is the first report of basophilic acute promyelocytic leukemia with the three-way translocation t(12;17;15) (p13; q24;q21).