Enteropathy-associated T-cell lymphoma (EATL), an uncommon lymphoma of intestinal intraepithelial T lymphocytes, occurs with a higher frequency in northern Europe due to association with celiac disease. Data on the occurrence of EATL in the Asian population, among whom celiac disease is very rare, are conflicting. This study aimed to characterize EATL encountered in the Chinese population in Hong Kong. Eighteen cases were identified, all fulfilling the criteria of type II rather than classical EATL. The patients, including 13 men and 5 women, had a median age of 62 years. Most presented with small bowel perforation, and there was no history of malabsorption. The clinical course was aggressive, with 14 of 16 patients dying of progressive disease or complications, usually within 1 year. The histologic features were practically identical in all cases. The central zone of the tumor showed ulceration with or without perforation and was characterized by monotonous transmural infiltration of the bowel by small-sized or medium-sized lymphoma cells with few admixed inflammatory cells and no coagulative necrosis. The peripheral zone featured lateral spread of lymphoma cells in the mucosa, accompanied by variable involvement of the submucosa and muscularis. In all cases, there was an intraepithelial lymphocytosis zone contiguous or discontinuous with the peripheral zone, which was characterized by infiltration of the intestinal epithelium by nonatypical small lymphocytes, and not accompanied by other histologic changes of enteropathy. The most common phenotype of the lymphoma cells was CD3+, CD5-, CD4-, CD8+, CD56+, TIA1+, CD30-, and Epstein-Barr virus, and 2 cases showed aberrant expression of CD20. A remarkable finding was that 14 (78%) cases expressed γδ T-cell receptor, and only 6 (33%) expressed αβ T-cell receptor (with 3 cases coexpressing both T-cell receptors and 1 case expressing neither). The immunophenotype of the intraepithelial lymphocytes was either discordant (particularly with respect to CD8 and CD56 expressions) or concordant with the lymphoma cells of the corresponding cases. Thus, this study shows that EATL occurring in the Chinese population is exclusively of type II. In contrast to several studies, intraepithelial lymphocytosis can be consistently demonstrated and this component seems to represent a precursor lesion of EATL rather than a manifestation of celiac disease. In view of the differences in epidemiology and clinicopathologic features, we believe it is justified to separate out type II EATL from the EATL category as a distinct form of lymphoma, for which we propose the designation "monomorphic intestinal T-cell lymphoma."

One week of RBC triple therapy with metronidazole and tetracycline is an effective anti-Helicobacter therapy. This regimen is more appropriate in areas of high prevalence of metronidazole resistance.

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We report two cases of primary thymic adenocarcinoma, a very uncommon neoplasm with limited information in the literature. Both patients were men (age 15 and 39 years). The first case was a mucinous carcinoma, a subtype of adenocarcinoma not previously recognized in the thymus. It comprised islands and strips of mucin-rich tumor cells floating in large pools of extracellular mucin. There was transition of carcinomatous epithelium to the attenuated epithelium of a thymic cyst. Immunostaining for high molecular weight cytokeratin furthermore highlighted in one area negatively stained tumor islands wrapped by positively stained residual thymic medullary epithelium, suggesting in situ origin of the carcinoma from the thymic epithelium. The second case was a papillary carcinoma with high nuclear grade and many psammoma bodies. It showed strong immunoreactivity for CD5 and did not stain for CA-125 as well as thyroid, pulmonary, and mesothelial markers. The findings in this study therefore broaden the morphologic spectrum of thymic adenocarcinomas to include a mucinous subtype. Review of the literature indicates that thymic adenocarcinomas usually arise from thymic cyst or type A thymoma, and the clinical outcome is variable.