Trimodality imaging of colonic lymphoma

A 59-year-old woman with low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the colon was referred for follow-up endoscopy, which was performed with a colonoscope equipped with autofluorescence imaging (AFI) and narrow-band imaging (NBI) functions (Olympus Evis Lucera; CF FH260AZL/I). Several small flat lesions were seen during otherwise normal colonoscopy. The lesions were minimally elevated, slightly reddish, and less than 5 mm in diameter; the submucosal vascular pattern was blurred, but covering mucosa appeared glossy during white-light imaging ([Fig. 1]). The tenuous abnormal vascular pattern was enhanced in narrow-band imaging ([Fig. 2], [3]) and autofluorescence imaging indicated a decreased autofluorescence signal from pathologic tissue ([Fig. 4]). Non-Hodgkin’s lymphoma tissue was revealed in biopsy samples ([Fig. 5]) and a pathologic clone of B lymphocytes was detected in flow cytometry ([Fig. 6]). To our knowledge this is the first report of trimodality imaging of colonic MALT lymphoma in the literature.

Fig. 1 Low-grade mucosa-associated lymphoid tissue lymphoma of the colon (asterisks; white-light endoscopy).

Fig. 2 Colonic lymphoma lesions enhanced by narrow-band imaging (the same view as in Fig. 1).

Fig. 3 Abnormal vascular pattern of lymphoma lesion under magnifying endoscopy (narrow-band imaging).

Fig. 4 Pale purple color of colonic lymphoma lesions under autofluorescence imaging (same view as in Fig. 1).

Fig. 5 Immunohistochemistry: infiltration of colonic submucosa and mucosa by small lymphoid cells of B-cell lymphoma (CD79-α staining).

Fig. 6 Flow cytometry. Colon biopsy was mechanically disintegrated. The malignant B lymphocytes were identified as a population of CD20-positive B cells.

Primary colonic lymphoma is rare, but more thorough investigation might well lead to higher reported rates of gastrointestinal involvement [1]. Solitary or multiple protrusions are the most common pattern of MALT lymphoma in the colon [2]. Abnormal vessel pattern as a typical endoscopic feature of bowel lymphoma has been described previously by our group [3].

The term “trimodality imaging” refers to conventional white-light imaging assisted by narrow-band and autofluorescence imaging. Narrow-band imaging is able to enhance the visualization of tissue microvasculature, while autofluorescence imaging shows up reduced autofluorescence, and both these attributes can improve the detection of colonic neoplasia [4].

In conclusion, the dampened autofluorescence signal on autofluorescence imaging and abnormal vascular pattern on narrow-band imaging can represent important endoscopic features of lymphoma deposit in colonic mucosa. Trimodality imaging can thus facilitate the detection of this otherwise potentially discreet disease in the colon.

References

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• 3 Kopáčová M, Rejchrt S, Tyčová V. et al . Tumorous neo-vascularization: a newly recognized endoscopic feature of intestinal non-Hodgkin lymphoma.  Endoscopy. 2007;  39 (Suppl 1) E93
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