Primary Cardiac Lymphoma: Echocardiography and F‐18‐Fluorodeoxyglucose Positron Emission Tomography in Selection of a Biopsy Site

A 63‐year‐old man was referred to our hospital because of a cardiac tumor. Transthoracic echocardiography revealed a rough, mobile tumor in the dilated right atrium, and transesophageal echocardiography showed that the tumor consisted of small, botryoidal masses. Catheter‐based biopsy carried a high risk of embolism. Therefore, we used F‐18‐fluorodeoxyglucose positron emission tomography (FDG‐PET), which revealed an abnormal accumulation in the right cervical lymph nodes, as well as in the heart. We safely performed biopsy of the lymph nodes and diagnosed the patient with primary cardiac lymphoma. We concluded that echocardiography and FDG‐PET are useful for selecting an appropriate biopsy site in primary cardiac lymphoma.     

First Japanese case of atypical progeroid syndrome/atypical Werner syndrome with heterozygous LMNA mutation

Atypical progeroid syndrome (APS), including atypical Werner syndrome (AWS), is a progeroid syndrome involving heterozygous mutations in the LMNA gene encoding the nuclear protein lamin A/C. We report the first Japanese case of APS/AWS with a LMNA mutation (p.D300N). A 53‐year‐old Japanese man had a history of recurrent severe cardiovascular diseases as well as brain infarction and hemorrhages. Although our APS/AWS patient had overlapping features with Werner syndrome (WS), such as high‐pitched voice, scleroderma, lipoatrophy and atherosclerosis, several cardinal features of WS, including short stature, premature graying/alopecia, cataract, bird‐like face, flat feet, hyperkeratosis on the soles and diabetes mellitus, were absent. In immunofluorescence staining and electron microscopic analyses of the patient's cultured fibroblasts, abnormal nuclear morphology, an increase in small aggregation of heterochromatin and a decrease in interchromatin granules in nuclei of fibroblasts were observed, suggesting that abnormal nuclear morphology and chromatin disorganization may be associated with the pathogenesis of APS/AWS.     

Poor responses to tyrosine kinase inhibitors in a child with precursor B‐cell acute lymphoblastic leukemia with SNX2‐ABL1 chimeric transcript

In addition to BCR, various rare fusion partners for the ABL1 gene have been reported in leukemia. We have identified the fusion gene SNX2‐ABL1 in a pediatric case of acute lymphoblastic leukemia (ALL), which has only once previously been reported in an adult patient. Cytogenetic analysis detected this fusion gene arising from a t(5;9)(q22;q34) translocation. ALL cells carrying a SNX2‐ABL1 fusion exhibited a BCR‐ABL1+ ALL‐like gene expression profile. The patient poorly responded to dasatinib but partially responded to imatinib. Treatment using tyrosine kinase inhibitors requires further investigation to optimize the genotype‐based treatment stratification for patients with SNX2‐ABL1 fusion.