Colonic Lymphoma

Axial (top) and coronal-reformatted (bottom) CT images show partial circumferential wall thickening (arrows) of the descending colon (C). Note smooth margin and homogeneous enhancement of bowel wall thickening, and disproportionate lack of colonic narrowing despite a large lesion. 

Facts:

• Lymphoma accounts for 0.2% - 1.2% of all colon malignancies
• Most common form of GI tract lymphoma is non-Hodgkin lymphoma (NHL)
• Most common sites of GI tract lymphoma is stomach, followed by small bowel
• For colonic lymphoma, most common site is cecum
• Nonspecific clinical signs and symptoms
• Due to rarity, Rx is not standardized. Often, it is surgically resected then chemotherapy is given

CT patterns of GI tract lymphoma:

• Nodular thickening of bowel wall
• Discrete polyp (causing intussusception)
• Long, distensible infiltrative lesion with ill-defined, thick walls with aneurysmal dilatation of the lumen
• Large exoenteric mass extending into adjacent soft tissues

Features differentiating lymphoma from adenocarcinoma of GI tract

• Bulky lymphadenopathy (lymphoma more likely)
• Marked luminal dilatation of bowel segment that is involved (lymphoma more likely)

Our case: Colonic mucosa-associated lymphoid tissue (MALT) lymphoma in a 67-year-old man.

References:

Buckley JA, Fishman EK. CT evaluation of small bowel neoplasms: spectrum of disease. Radiographics 1998;18:379.

Bairey O, et al. Non-Hodgkin lymphomas of the colon. Hematol 2006;8:832.