Primary non-Hodgkin lymphoma (NHL) of the gastrointestinal tract (GI) is rare with incidence of 10-15% of all NHL cases and 1-4% of all GI tumors. The most common sites of involvement include the stomach, small intestines, colon and rectum. The presentation is usually non-specific leading to delay in diagnosis. A 49-year-old male patient with history of gastroesophageal reflux disease (GERD) presented with a 3-month history of abdominal discomfort and early satiety, this was associated with fatigue, night sweats and 20 lbs weight loss. On physical examination, he had tender right sided cervical lymphadenopathy (LAD) with several palpable, tender abdominal masses. Laboratory work up was significant for microcytic anemia with hematocrit of 39.8, mean corpuscular volume (MCV) 79.8, iron level 42 and iron saturation 11.1%. Ultrasonography (US) of the abdomen showed LAD near the umbilicus. Given his symptoms and laboratory work up, he underwent a colonoscopy that showed a single 1 cm ulcer in the descending colon (Fig. 1). Biopsy of the ulcer showed cells with expansion of the lamina propria by large atypical lymphocytes with irregular nuclear contour, single prominent nucleoli and moderate cytoplasm. Immunohistochemical stains of the cells were positive for CD20 and CD79a. The final diagnosis was diffuse large B-cell lymphoma (DLBCL), germinal center B cell-like (GCB) subtype. Positron Emission Tomography - Computed Tomography (PET-CT) was positive for uptake in cervical, mediastinal, and abdominal nodes. He was started on combination chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP). He finished 6 cycles of R-CHOP with a negative repeat PET-CT consistent with remission.1550 Figure 1 No Caption available.Primary colorectal lymphoma is rare representing only 0.2 — 0.6% of all colorectal malignancies. The most common symptoms at presentation are abdominal pain and weight loss. DLBCL is the most common histological subtype. Computed Tomography (CT), US and PET-CT are helpful in suggesting the diagnosis by locating the tumor and its extension. Colonoscopy usually shows a fungating mass, infiltrative or ulcerative lesions. Distinct types of DLBCL are identified by gene expression profiling with the most common subtypes are GCB and activated B cell-like (ABC) DLBCL. The GCB has better survival compared to ABC. Management of DLBCL usually involves chemotherapy, radiation, surgery or a combination with R-CHOP chemotherapy being first line.