Plasmablastic Lymphoma: A Clinicopathological Study from a Tertiary Care Cancer Center in South India.

Plasmablastic lymphoma (PBL) is a rare aggressive B cell lymphoma that is commonly encountered in patients with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). In this case series, we describe the clinicopathological features of cases of PBL seen at a tertiary care center in South India.  Medical records of patients diagnosed with PBL between January 2009 and November 2017 were reviewed. PBL was defined as per the World Health Organization 2016 classification for hematopoietic and lymphoid neoplasms. The slides were reviewed with hematoxylin and eosin along with immunohistochemistry (IHC) including CD45, CD20, PAX5, CD79a, CD3, CD5, CD138, MUMI, EMA, ALK, and Ki67. Epstein-Barr virus (EBV) association was documented by rapid in situ hybridization (RISH) studies wherever possible. The demographic data, clinical presentation, treatment details, and outcomes are elaborated using descriptive statistics.  During the study period, nine patients with PBL were identified. The median age at presentation was 47 years (range: 36-54 years). All patients had associated HIV/AIDS, eight (89%) had extranodal disease, and six (66%) had advanced clinical stage (stage III). All biopsies were positive for CD45, CD138, and MUM1, and negative for CD79a and T cell markers with a high Ki67 proliferation index (85-90%); CD20 was faint positive in one patient, and CD56 was positive in one (11%) patient. EBV-RISH was tested in two patients and was positive in one. Bone marrow was uninvolved in all the cases. At the time of last follow-up, three patients were alive. Treatment details were available in six patients. With frontline therapy, four patients achieved a complete remission (CR) and one patient developed progressive disease. Three of four patients in CR are alive till the last follow-up.  PBL is a rare form of lymphoma with predominant association with HIV, extranodal location, and characteristic IHC pattern.