Presentation
Iron deficient anemia.
Patient Data
Circumferential mural thickening of the mid small bowel with serosal surface irregularity. No luminal narrowing. Small bowel mesneteric root fat stranding. Adjacent enlarged mesenteric node. No other small bowel lesion is identified. The stomach, duodenum, appendix, large bowel, and rectum are normal.
No further abdominal or pelvic lymphadenopathy. No ascites.
Small liver low-density in segment 5 is non-specific. The remainder of the liver is normal.
The patient proceeded to small bowel resection.
HISTOPATHOLOGY
MACROSCOPIC: Small bowel – a small segment of small bowel, 115 x up to 35mm, with attached mesentery 100 x 35 x 25mm. One end is painted blue, other end green. Approximately 30mm from the blue end, there is dilatation of the segment, 35mm in length and up to 35mm in diameter. There is also whitish discolouration of the serosal surface. Otherwise, the serosa appears intact. On sectioning, corresponding to the dilated segment, there is a non–obstructing circumferential lesion, 35mm in diameter x 55mm across. The lesion is at least 40mm from the green margin and at least 25mm from the blue margin. The lesion appears to be involving the muscularis propria and focally involves the adjacent mesentery and bulges to the serosa (suspicious for peritoneal invasion). A total of 25 possible lymph nodes (one apical) are identified with a maximum dimension of 8 x 5 x 9mm.
MICROSCOPIC:
Sections of the small bowel lesion show a diffuse infiltrate of intermediate sized lymphoid cells with irregular nuclear membranes, granular chromatin and minimal pale eosinophilic cytoplasm. Mitotic figures are readily identified. The overlying mucosa is ulcerated and the infiltrate extends into the mesenteric fat. The background intact small bowel mucosa is benign.
Immunohistochemistry
CD20: positive
PAX5: positive
CD10: positive
BCL6: positive
BCL2: patchy staining, favor >50% (positive)
CD21: patchy positivity in lesional cells
CD23: negative; no follicular structures identified
CD3: stains background T cells
CD5: stains background T cells
Cyclin D1: negative
CD30: negative
MUM1: negative
c–MYC: negative
CD138: negative
Ki67: variable, with foci up to 90%
DIAGNOSIS: Small bowel: Diffuse large B cell lymphoma, germinal center B–cell (GCB) subtype, involving small bowel.
Case Discussion
This case demonstrates the typical appearances of small bowel lymphoma with mural thickening without luminal thickening, compared with adenocarcinoma, which usually results in luminal narrowing and bowel obstruction. Inflammatory bowel disease (i.e. Crohn disease) is within the imaging differential although usually will not have serosal surface irregularity and enlarged mesenteric nodes.
Case courtesy of Dr Jonathan Shulman.
Unable to process the form. Check for errors and try again.