GASTROENTEROLOGY ARTICLE OF THE WEEK
October 2, 2003
Ahmad A, Govil Y, Frank BB. Gastric mucosa-associated lymphoid tissue lymphoma. Am J Gastroenterol 2003;98:975-986.
1. Primary gastric lymphoma compared to secondary gastric lymphoma,
a. both affect primarily the antrum and body of the stomach
b. multifocal involvement, often including the duodenum is more common in
primary gastric lymphoma
c. most 1ry and 2ry lymphomas have similar endoscopic appearance – diffuse
submucosal tumor infiltration rather than bulky localized disease
d. large, bulky lesions are more typical of primary gastric lymphoma
2. EUS in MALT:
a. is useful for staging the lesion
b. may select patients more likely to respond to H. pylori eradication
c. if massive infiltration of the gastric wall or suspected nodal metastasis are
detected, the diagnosisof MALT should be questioned
d. can differentiate PGL from secondary lymphoma in most cases.
3. Treatment of MALT associated with H. pylori
a. eradicate H. pylori and repeat EGD with biopsies in 1-2 months to confirm that
the MALT lymphoma is gone.
b. In initial biopsies are negative for H. pylori, confirm negativity with serologic
testing.
c. It may take 12 months for the histologic features of MALT to disappear after
H. pylori eradication.
d. After H. pylori eradication and endoscopic confirmation of resolution, follow-up
is life-long with yearly endoscopy and biopsies.
True or False
4. The normal stomach lacks lymphoid tissue, H. pylori infection causes lymphoid follicles to appear in the stomach.
5. MALTomas are T cell lymphomas.
6. Maltomas with predominance of plasma cells may represent plasmacytomas and do not respond to H. pylori eradication, instead, radiation is the therapy of choice.
7. If a patient with MALT lymphoma tests negative for H. pylori, eradication should be done anyhow.
8. MALT lymphoma is almost always associated with CagA (+) H. pylori infection.
9. MALT lymphoma fails to respond to H. pylori eradication when the monoclonal B cell clone is no longer dependent on the inciting antigenic stimulus to proliferate.
10. After H. pylori eradication in patients with MALT, repeat endoscopy and biopsy should be done every 6 months for the first 2 years, then yearly
11. The lymphoepithelial lesion (invasion of the epithelial lining of the gastric glands by lymphoid cells) is the histologic hallmark of MALT.
12. Prior to initiation of therapy for MALToma, CT scan and EUS should be obtained, CT is not very sensitive in detect perigastric lymph node metastasis.
13. Up to 25% of MALTomas may be missed by doing routine endoscopic gastric biopsies.