A 43-year-old man known case of retropositive illness presented with abdomen pain of 15 days and loose stools for 10 days. Loose stools were foul smelling and blood stained. The patient was a known case of type 2 diabetes and retroviral illness on highly active antiretroviral therapy (HAART). General physical examination was normal. On examination an irregular mass was palpable in the right iliac fossa and right flank. The mass was hard in nature; irregular with restricted mobility. There was no palpable liver or spleen. CT of the abdomen and pelvis revealed a well-defined heterogeneously enhancing hypodense mass lesion measuring 16×11.7×12 cm involving the ileocaecal region and extending medially and inferiorly to sigmoid colon and rectum. A colonoscopy showed a proliferative highly vascular mass 15 cm from anal verge at the rectosigmoid junction. Histopathology revealed sheets of neoplastic lymphoid cells in rectal wall suggestive of non-Hodgkins lymphoma.