PTPRC and primary effusion lymphoma: The lymphoma cells in extracavitary-only PEL were less often positive for CD45 (69.2% vs. 96.2%, p = 0.01), CD30 (60.0% vs. 81.5%, p = 0.09), and EMA (26.7% vs. 100%, p = 0.0005), and were more often positive for EBER (76.9% vs. 51.9%, p = 0.06) and CD3 expression (33.3% vs. 13.3%, p = 0.07) (Table 2).