INTRODUCTION Double-hit lymphoma (DHL) is a heterogeneous group of lymphomas that is neither classified as diffuse large B-cell lymphoma (DLBCL) nor as Burkett's lymphoma (BL), having features intermediate between these two separate entities. This led to a new category of lymphoma in 2008 World Health Organization (WHO) classification: “B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL)”. 1 In DHL, there are genetic translocations of two genes, i.e. C-myc and Bcl2 that make it refractory to standard chemotherapy regimens and, therefore, a worse prognosis. 2-3 We report an 82-year Pakistani patient who presented with lump in his left groin with a short history of one month; and despite intensive course of standard chemotherapy and radiation therapy, died of disease with progression. CASE REPORT An 82-year male was admitted in private hospital for low grade fever, night sweats and left groin lump. He was found to have an enlarging inguinal mass on the left side measuring 6 cm, which had been present for one month. His lactate dehydrogenase (LDH) was 459 U/L (reference range: < 480), urea 72 mg/dl (reference range: 10 - 50), creatinine 2.1 mg/dl (reference range: 0.9 - 1.2), hemoglobin 9.9 G/dl and hematocrit 25.3%. Radiographic imaging was normal except left inguinal mass and bilateral hazy cardiopulmonary angles on X-ray chest. Sonological studies showed bilateral grade I echogenic kidneys with simple cyst on left side and prostatomegaly. The inguinal mass was biopsied and histopathology showed tumor composed of medium-sized cells arranged in sheets that were discohesive and had condensed nuclear chromatin and multiple nuclei. Apoptosis and frequent mitotic figures were also noted. The immunohistochemistry stains showed intense positivity of CD20, Bcl2, C-myc (70 - 80%) and Ki-67 (proliferative index) was very high (> 95%) as shown in Figure 1. Journal of the College of Physicians and Surgeons Pakistan 2016, Vol. 26 (10): 865-867 865 CASE REPORT Double-Hit Lymphoma - A Rare Subset of Diffuse Large B Cell Lymphoma with Poor Outcome Sajid Zaman, Jawad A. Gillani and Rashid Rasheed ABSTRACT Double-hit lymphoma (DHL) has been identified as a subset of diffuse large B-cell lymphoma with poor clinical outcomes. It is because of genetic translocation of C-myc and Bcl2 gene that make it more aggressive and un-responsive to conventional and salvage treatments. DHL is an extremely rare entity of non-Hodgkin's lymphoma (NHL) having no established incidence data so far. In literature very limited data is available to guide therapeutic decisions and despite aggressive chemotherapy followed by autologus hematopoietic cell transplantation, outcomes still remain poor. Herein, we report a case of 82-year Pakistani patient who presented with left groin lump. Incision biopsy established the diagnosis of DHL. Despite intensive course of standard chemotherapy and radiation therapy, he died with progression of disease. Key Words: Double-hit lymphoma. Genetic translocation. Burkett's lymphoma. Intermediate lymphoma. Diffuse large B cell lymphoma. Department of Radiation Oncology, Institute of Nuclear Medicine, Oncology and Radiotherapy (INOR), Abbottabad. Correspondence: Dr. Sajid Zaman, Department of Radiation Oncology, Institute of Nuclear Medicine, Oncology and Radiotherapy (INOR), Abbottabad. E-mail: drszaman2000@yahoo.com Received: August 19, 2015; Accepted: Febrruary 20, 2016. Figure 1: Hematoxyline and Eosin stain (A). Immunohistochemical demonstrating intense stain positivity of CD20 (B), Ki67 (C), Bcl2 (D) and C-myc (E).