Case Presentation: A 57-year-old male with HIV, heart failure with reduced ejection fraction, and hypothyroidism initially presented for dyspnea on exertion, found on EKG to have electrical alternans. Telemetry showed intermittent type2 second degree AV block. Transthoracic echocardiogram was notable for large pericardial effusion, ejection fraction 35%, grade 1 diastolic dysfunction, early diastolic right ventricular collapse, and mitral/ thoracic valve inflow respiratory variation suggestive of echocardiographic tamponade. TSH 66 and FT4 0.11 were suggestive of severe hypothyroidism, thought potentially causing conduction abnormalities and pericardial effusion. Patient subsequently underwent pericardiocentesis of 1.2 L serous fluid. The pericardial fluid was notable for 29,000 cells (neutrophils 16%, lymphocytes 3%, monocytes 13%), glucose < 2, LDH >5000, protein 5.6 meeting exudative effusion criteria. Concurrent left heart catheterization did not show obstructive coronary artery disease. Given exudative effusion with atypical cytology, further workup was started. Hematology and infectious disease teams were consulted. Most notable finding involved pathology results positive for HHV8+ and CD30+, concerning for malignancy. Patient was subsequently diagnosed with primary effusion lymphoma (PEL). He was initiated on C1 CEOP (cyclophosphamide, etoposide, vincristine, prednisone) chemotherapy during same hospital course for prompt management.

Discussion: PEL is a rare HIV-associated non-Hodgkin’s lymphoma, accounting for approximately 4% of HIV-associated NHL and < 1% of non-HIV-related lymphomas. It has a male predominance of 6:1. HHV8 is implicated in the oncogenesis of PEL and although the exact mechanisms are not fully understood, it has been theorized to promote oncogenesis via viral transcripts during the latent phase of HHV8 infection. PEL has a unique clinical presentation in having a predilection for arising in body cavities including pleural spaces, pericardium, and peritoneum. Factors associated with poor outcome with this diagnosis in patients with HIV include poor performance status and the absence of HAART prior to PEL diagnosis. Despite this patient being compliant with his HAART therapy, the risk of having PEL remains. Treatment is usually with CHOP based therapy but overall prognosis of PEL is poor, with overall 1 year survival approximately 30%.

Conclusions: Isolated cardiac lymphomas should be considered for HIV patients presenting with pericardial effusions in order to properly determine the appropriate therapy. In this case hypothyroidism was a red herring, ultimately pericardial fluid analysis offered the more definitive diagnosis.