[Clinicopathological features of primary cardiac CD5-positive and bcl-2 and C-MYC double expression diffuse large...

Objectives: To investigate the clinicopathological features, therapy and prognosis of primary cardiac CD5-positive diffuse large B-cell lymphoma with C-MYC and bcl-2 double expression. Methods: Two cases diagnosed at Guangdong Provincial People's Hospital were included, the clinical data were collected; the tumor morphology, immunophenotypic profiles, therapy and prognosis were analyzed. Results: Case 1 was a 55-year-old man and case 2 was a 61-year-old women. Intraoperatively, both cases showed large masses in the right atrium or ventricle, involving adjacent tissue. Pathologically, the tumors were composed of diffusely infiltrating large lymphoid cells with high mitotic activity and apoptosis. The tumor cells were positive for CD20, CD5, bcl-6, MUM1, C-MYC and bcl-2, and the Ki-67 index was equal or greater than 90%. Case 1 had bcl-6, but not bcl-2 or MYC gene rearrangements. No MYC, bcl-2 or bcl-6 gene rearrangements were detected in case 2. Case 1 defaulted chemotherapy after operation and died 1 month after diagnosis. Case 2 was treated with 4 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) therapy after surgery and attained partial remission, and was then treated with apatinib and ibrutinib, and remained stable 18 months after initial diagnosis. Conclusion: Primary cardiac CD5-positive diffuse large B-cell lymphoma with C-MYC and bcl-2 double expression usually shows large infiltrative mass in the right atrium or ventricle, non-germinal center like immunophenotype and high proliferation index, and this may contribute to the aggressiveness of primary cardiac lymphoma.