Cardiac involvement by malignant lymphoma: a clinicopathologic study of 25 autopsy cases based on the WHO classification.

As cardiac involvement by malignant lymphoma (ML) is relatively uncommon and antemortem diagnosis is difficult, details of this condition remain to be elucidated. To clarify clinicopathologic features of cardiac lymphoma (CL), 25 autopsy cases were studied. Each was rediagnosed according to the World Health Organization (WHO) classification, and clinicopathologic characteristics were investigated by tumor phenotype. The study subjects were 13 males and 12 females with a mean age of 53.4 years. All cases were secondary CL and were not diagnosed as CL before death; 14 cases (56%) were of B-cell and 11 (44%) of T-cell (including natural killer cell) phenotype. Nasal and nasal-type natural killer/T-cell lymphomas (NKTLs) accounted for five (20%). Cardiac manifestation was evident in eight (32%), with hematogenous infiltration as the most common pattern of tumor spread. Some B-cell CLs (n=3) were complicated by cardiac tamponade and heart failure (HF), and T-cell CLs (n=5), including three nasal NKTLs, also featured arrhythmia and sudden death. The incidence of T-cell phenotype was significantly elevated for CLs (p<0.05), especially for CLs with cardiac manifestation (p<0.01), compared with that for MLs in general. Our results indicate that T-cell lymphomas, compared with B-cell lymphomas, invade the heart more frequently and aggressively and are associated with a variety of cardiac manifestations. Where cardiac involvement is suspected, aggressive diagnostic procedures are warranted, especially with MLs having a T-cell phenotype. In cases of nasal NKTL, particular attention is necessary.