Autopsy case of cardiac mantle cell lymphoma presenting with recurrent pulmonary tumor embolism after chemotherapy.

A 78-year-old Japanese man presented to the emergency department with a sore throat and fever that worsened over 3 weeks. A tonsil biopsy led to the diagnosis of pleomorphic mantle cell lymphoma (MCL) that had infiltrated the right adrenal gland, inferior vena cava, and right atrium (RA). Although the patient's cardiac tumor had high mobility, his hemodynamic state was stable, and he did not present with fatal arrhythmia. Therefore, we first introduced chemotherapy. However, the patient developed recurrent pulmonary embolisms (PEs) and died after starting chemotherapy. An autopsy revealed that the MCL had invaded the large vessels, causing the PEs. Although the high mobility of cardiac tumors is known to increase the risk of PE in diffuse large B-cell lymphoma (DLBCL), optimal management of cardiac MCL remains to be elucidated owing to its rarity. To the best of our knowledge, this is the first report of cardiac MCL with posttreatment PE development in a Japanese patient. It is worth considering preventive surgery before treatment not only in DLBCL, but also in MCL based on the mobility of the cardiac tumors. Our case highlights the need for close communication between hematologists and cardiologists to treat cardiac MCL.

First report of familial mixed phenotype acute leukemia: shared clinical characteristics, Philadelphia translocation, and germline variants.

While our understanding of the molecular basis of mixed phenotype acute leukemia (MPAL) has progressed over the decades, our knowledge is limited and the prognosis remains poor. Investigating cases of familial leukemia can provide insights into the role of genetic and environmental factors in leukemogenesis. Although familial cases and associated mutations have been identified in some leukemias, familial occurrence of MPAL has never been reported. Here, we report the first cases of MPAL in a family. A 68-year-old woman was diagnosed with MPAL and received haploidentical stem cell transplantation from her 44-year-old son. In four years, the son himself developed MPAL. Both cases exhibited similar characteristics such as biphenotypic leukemia with B/myeloid cell antigens, Philadelphia translocation (BCR-ABL1 mutation), and response to acute lymphoblastic leukemia-type chemotherapy. These similarities suggest the presence of hereditary factors contributing to the development of MPAL. Targeted sequencing identified shared germline variants in these cases; however, in silico analyses did not strongly support their pathogenicity. Intriguingly, when the son developed MPAL, the mother did not develop donor-derived leukemia and remained in remission. Our cases provide valuable insights to guide future research on familial MPAL.