A Rare Case of Diffuse Large B Cell Lymphoma Presenting as a Cardiac Mass

Patient: Female, 57-year-old Final Diagnosis: Mediastinal diffuse large B cell lymphoma infiltrating the heart as a right atrial cardiac mass Symptoms: Cough • dyspnea • fatigue • weight loss Medication: — Clinical Procedure: — Specialty: Oncology OBJECTIVE: Rare disease BACKGROUND: Primary mediastinal diffuse large B cell lymphoma (DLBCL) presenting as a large intracardiac tumor is extremely rare and has not been significantly reported in the literature. Cardiac lymphoma consists of 2 subtypes: mediastinal DLBCL invading the heart and primary cardiac lymphoma. Both subtypes have a poor prognosis and are treated similarly. Mediastinal DLBCL is a life-threatening condition that, if diagnosed early, has a better survival rate. This is a rare case of a mediastinal DLBCL invading the right atrium as a large intracardiac mass, causing partial obstruction of the tricuspid valve without hemodynamic compromise. CASE REPORT: A 57-year-old female presented with unintentional weight loss, fatigue, exertional dyspnea, and cough for 8 weeks. Transesophageal echocardiogram showed a mass (3.5×3.5 cm) in the posterior wall of the right atrium partially obstructing the tricuspid valve. Biopsy revealed DLBCL. Given new-onset lymphoma, a human immunodeficiency virus (HIV) test was done and came back positive. CD4 count was 100 cells/mm(3). Chemotherapy was initiated with rituximab, cyclophosphamide, epirubicin, vincristine, and prednisone (R-CHOP). Highly active anti-retroviral (HAART) therapy was started for HIV. After treatment with R-CHOP and HAART, the patient had complete resolution of the mass and symptoms on follow-up imaging and evaluation at 6 months. CONCLUSIONS: Mediastinal DLBCL invading the heart is a life-threatening form of non-Hodgkin’s lymphoma (NHL) and early diagnosis and treatment is critical as prognosis is poor especially if diagnosed in later stages of the disease. Testing for HIV is important as 5% of HIV patients are susceptible to developing NHL.