Hiv-Associated Lymphoma

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A 39-year-old man with AIDS experienced worsening shortness of breath, cytopenia, and fever and was admitted to Baylor University Medical Center. The patient also reported symptoms of anorexia, diarrhea, abdominal pain, and generalized body pain. The physical examination showed cachexia; a large perineal Kaposi sarcoma tumor, as well as scattered Kaposi sarcoma lesions on his face, neck, back, and chest; dependent edema in the legs and scrotum; a scrotal ulcer; and abdominal distension with ascites and tenderness. No lymphadenopathy or hepatosplenomegaly was noted. A lung infiltrate and right-sided pleural effusion were evident, and the possibility of parapneumonic effusion was considered. A complete blood count demonstrated leukopenia (white blood cell count, 500 K/uL), anemia (hemoglobin, 8.6 g/dL), and thrombocytopenia (platelet count, 19,000 K/uL), with a virtual absence of CD4+ cells (<1%). The absolute lymphocyte count was 288 cells/L. HIV-1 RNA quantification by polymerase chain reaction was <50. The patient's blood cultures were also positive for Streptococcus viridans. The source of the infection was believed to be the skin, in association with Kaposi sarcoma. The patient was treated with broad-spectrum antibiotics, and follow-up blood cultures showed resolution of the infection. The pleural effusion was drained and sent for cytologic evaluation. Results showed highly atypical, pleomorphic lymphoid cells (Figures ​(Figures11 and ​and22). Usual B and T cell markers (CD3, CD5, CD10, CD15, CD20, CD79a, PAX5) were negative, and activation markers (CD30 and MUM1) were positive in this tumor. CD138 showed a minimal to no staining pattern (although most PELs show a positive reaction). The tumor proliferation marker MIB-1 (Ki-67) showed strong positivity, with staining of 75% of cells (Figure ​(Figure33). The cells were positive for human herpesvirus 8 (HHV8) and Epstein-Barr virus (EBV) (Figure ​(Figure44). The EBV copy number in the pleural fluid was 105,000/mL. Figure 1 (a) Highly cellular smear with multiple aggregates of mononuclear cells (×10, hematoxylin and eosin stain [H&E]). (b) Note the pleomorphic nature of the cells (×20, H&E). (c) Some of the cells show plasma cytoid features ... Figure 2 High-power view (×40, H&E) of primary effusion lymphoma. Note the multinucleated tumor cell with prominent macronucleoli (arrow) in a background of highly atypical pleomorphic mononuclear cells. Figure 3 Immunohistochemistry results showed positive staining (×10) for (a) CD30, (b) MUM1, and (c) MIB1 (75%). Figure 4 (a) Primary effusion lymphoma with a distinct, strong positive reaction to HHV8 (×10). (b) Ebstein-Barr virus–encoded small RNAs (EBER) staining showed scattered, slightly positive cells (×10). Although the differential diagnosis based on the clinical findings would include pyothorax-associated lymphoma, Burkitt lymphoma, lymphomatous effusion of disseminated lymphoma, malignant melanoma, and pleomorphic non–small cell carcinoma, the absence of HHV8 in each of these lymphomas eliminated them from consideration. Primary effusion lymphoma (PEL) was diagnosed.