A 27-year-old woman with pancytopenia was admitted to our hospital. Bone marrow aspiration revealed 52.2% myeloperoxidase-positive myeloblasts, leading to a diagnosis of acute myeloid leukemia. While a screening test for chimeric genes related to leukemia initially yielded negative results, including for the CBFB::MYH11 fusion gene, G-banded karyotyping uncovered the presence of inv (16)(p13.1q22). Further investigation by fluorescence in situ hybridization (FISH) confirmed the split signals for CBFB. A second screening test for leukemia-related chimeric genes with different PCR primers revealed the elusive CBFB::MYH11 fusion gene. Subsequently, the type I CBFB::MYH11 fusion gene was identified through exhaustive exploration using RNA sequencing for fusion gene discovery. This exceptional case highlights the existence of a distinctive subtype of CBFB::MYH11 that may yield false-negative results in conventional chimeric fusion screening, thus emphasizing the indispensable utility of PCR primer modification, FISH, and RNA sequencing in the investigative process.

An 88-year-old man became unconscious and was admitted to our hospital due to severe anemia. Extensive subcutaneous hemorrhage around the chest and back and pectoralis major muscle hematoma were observed. Coagulation screening tests showed moderately reduced factor XIII/13 (FXIII) activity. During hospitalization, the patient had repeated bleeding events in the gastrointestinal tract and muscles, leading to hemorrhagic shock. We suspected the presence of FXIII inhibitors from FXIII infusion test results. The cross-mixing test for cross-linking of fibrin revealed inhibition of polymerization of α-chain and α₂-plasmin inhibitor incorporation into fibrin. In addition, by detecting IgG autoantibody to thrombin-activated FXIII, we confirmed the presence of type Ab anti-FXIII-A subunit autoantibody, which represses the catalytic subunit activity of activated FXIII. Autoimmune FXIII deficiency should be considered when a patient presents with severe hemorrhagic diathesis with no other cause than moderately reduced of FXIII activity, as reported in this case.

Here we present the case of a 50-year-old woman with chronic myeloid leukemia who received nilotinib as initial treatment. After about 2 years of nilotinib therapy, she developed headache, blurred vision, impaired consciousness, and marked hypertension. Posterior reversible encephalopathy syndrome (PRES) was diagnosed, and was strongly suspected to be a vascular adverse event caused by nilotinib. Nilotinib was withheld and the patient was treated with antihypertensive drugs under ventilator management. Her symptoms resolved quickly. The most likely cause of PRES is systemic arterial hypertension and endothelial dysfunction due to direct injury leading to dysfunction at the level of the blood-brain barrier, along with the resultant vasogenic edema. PRES has been reported with some tyrosine kinase inhibitors, but this is the first case of PRES during nilotinib treatment.

der(1;7)(q10;p10) is a derivative chromosome generated by an unbalanced translocation between chromosomes 1 and 7 during DNA replication. It was first described in 1980, over 40 years ago, in a case report of three patients with myelofibrosis and myeloid metaplasia. This unbalanced translocation has been identified as a characteristic entity within myeloid neoplasms. Recent clinical and genetic studies comparing der(1;7)(q10;p10)(+) against −7/del(7q) have revealed that patients with der(1;7)(q10;p10)(+) MDS have a better prognosis and a unique mutational profile. This review discusses the clinical and genetic features of der(1;7)(q10;p10)(+) myeloid neoplasms.