1. Case 1  US-guided needle biopsy Consistent with diffuse large B-cell lymphoma

3. Final Diagnosis  Primary small bowel lymphoma  CTx (R-CHOP) #2.

4. 2016/02/122016/04/07

5. Gastrointestinal Lymphoma  Lymphoid elements occur in the lamina propria & SM  Primary lymphomas: usually involve one site  Secondary lymphomas: typically, multiple sites involved  NHL > HD  Stomach > small bowel > colon > esophagus  RFs HIV infection, immunosuppression after solid organ TPL H.pylori infection, Celiac disease, IBD Increased in Western with increasing incidence of HIV infection

6. Gastrointestinal Lymphoma  Staging I: tumor confined to GIT, single primary site, and multiple non- contiguous lesions II: tumor extends into the abdominal cavity from the primary GI site - II1, local nodal involvement; II2, distant nodal involvement III: penetration through serosa to involve adjacent organs or tissues IV: disseminated extranodal involvement or a GIT lesion with supra- diphragmatic nodal involvement

7. Small Bowel Lymphoma  20-30% of all primary GI lymphomas  Distal ileum (m/c): the greater amount of lymphoid tissue  CT findings Circumferential bulky mass in the intestinal wall, often a/w extension into the SBM and regional LNs May ulcerate & perforate into the adjacent mesentery (sterile abscess) No desmoplastic response; obstruction is uncommon May mimic adenoca with bowel obstruction, and infiltration into adjacent structures

8. Small Bowel Lymphoma  CT findings Aneurysmal dilatation of the lumen d/t replacement of the muscularis propria and destruction of the autonomic nerve plexus A focal, polypoid, homogeneous intraluminal mass without wall thickening or LAP Peritoneal lymphomatosis: rare - DDx Peritoneal carcinomatosis, TB peritonitis  US: hypoechoic; circumferential wall thickening

9. Small Bowel Lymphoma  T-cell lymphoma m/c in jejunum Higher prevalence of multifocal involvement and bowel perforation Usually mild to moderate bowel wall thickening  GI lymphoma Bulky mass or diffuse infiltration Preservation of fat planes Multiple site involvement Associated bulky LAP

10. References RadioGraphics 2007; 27:1371-1388 Radiology 1999; 211:183-187 RadioGraphics 1990; 10:985-998