Novel Mutations in a Lethal Case of Lymphomatous Adult T Cell Lymphoma with Cryptic Myocardial Involvement

The autopsy of a 65-year-old diabetic African American male revealed significant left myocardial involvement by adult T-cell leukemia/lymphoma (ATLL) despite normal pre-mortem fluorodeoxyglucose (FDG) uptake by positron emission tomography/computed tomography (PET/CT). Due to pre-existing diabetic cardiomyopathy with reduced ejection fraction (EF) and compatible imaging studies, cardiac lymphomatous involvement was not suspected. While peripheral blood was negative for leukemia, next-generation sequencing of a lymph node revealed at least eight novel mutations (AXIN1, R712Q, BARD1 R749K, CTNNB1 I315V, CUX1 P102T, DNMT3A S199R, FGFR2 S431L, LRP1B Y2560C and STAG2 I771M). These findings underscore a diagnostic pitfall in a rare lymphomatous variant of ATLL infiltrating myocardium and contribute to its molecular characterization.