Primary cardiac diffuse large B-cell lymphoma with activated B-cell-like phenotype.

Area of Science:

• Cardiovascular Pathology
• Hematologic Oncology
• Immunohistochemistry

Background:

• Primary cardiac lymphoma (PCL) is an exceptionally rare malignancy with a poor prognosis.
• PCL often presents with non-specific symptoms, mimicking more common cardiac tumors such as myxoma.
• Accurate and timely diagnosis is crucial for effective management.

Observation:

• A case of diffuse large B-cell type PCL in a 38-year-old immunocompetent male is presented.
• The patient initially presented with superior vena cava syndrome and the tumor was surgically removed, presumed to be a myxoma.
• Histological examination revealed a large cell lymphoma with an activated B-cell (ABC)-like phenotype, confirmed by CD45, CD20, MUM1/IRF4, and FOXP1 expression.

Findings:

• The patient received four cycles of Rituximab with CHOP (cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone).
• Initial treatment led to complete tumor regression.
• However, the patient experienced a relapse and ultimately succumbed to the disease, underscoring the aggressive nature of PCL.

Implications:

• The aggressive clinical course of this PCL case may be associated with its activated B-cell (ABC)-like immunophenotype.
• This case emphasizes the importance of considering PCL in the differential diagnosis of cardiac masses, especially when clinical presentation is atypical.
• Further research into the specific biological drivers of PCL, particularly those related to ABC-like phenotypes, is warranted to improve therapeutic strategies.