Distribution Of Lymphoid Neoplasms In China: Analysis Of 2371 Cases Primary Intestinal T-cell And NK-cell Lymphomas: A Clinicopathological And Molecular Study From China

Distribution of Iymphoid neoplasms in China:Analysis of 2371 casesSeveral reports have shown that the subtype distribution of Iymphoid neoplasms is different between Asian and Western populations. To estimate the distribution of Iymphoid neoplasms in China, we conducted a comprehensive analysis of subtype, age, sex, and lesion primarily biopsied/resected distribution patterns of 2371 Iymphoid neoplasms diagnosed during 2004-2008 at four large hospitals in China according to World Health Organization classifications. Of the total 2371 patients, mature B-cell neoplasms accounted for 68.20%of all Iymphoid neoplasms, mature T/NK-cell neoplasms for 21.17%, Hodgkin lymphoma for 7.42%, and precursor Iymphoid neoplasms for 3.21%. The most common subtype was diffuse large B-cell lymphoma (35.68%), followed by extranodal marginal zone B-cell lymphoma (9.62%), classical Hodgkin lymphoma (7.21%), B-cell Iymphoid neoplasm, not otherwise specified (NOS) (5.82%), peripheral T-cell lymphoma, NOS (5.53%), T/NK-cell Iymphoid neoplasms, NOS (5.44%), and extranodal NK/T-cell lymphoma, nasal type (5.02%). For most Iymphoid neoplasm subtypes, male subjects showed higher rates than female subjects, with an average Male/Female ratio of 1.62. Most mature non-Hodgkin lymphomas were diseases of adults (mean age,52.2 yr). whereas precursor Iymphoid neoplasms were found in young individuals (mean age,25.3 yr). In summary, our study showed that the epidemiologic features of Iymphoid neoplasms in China are distinct from those in Western countries and similar in many ways to those in other countries in the Far East.Primary intestinal T-cell and NK-cell lymphomas:a clinicopathological and molecular study from ChinaIn China, which is a non-endemic area for celiac disease, primary intestinal T-cell and natural killer (NK)-cell lymphomas (PITNKL) might comprise heterogeneous subtypes. Both type II enteropathy-associated T-cell lymphoma (EATL) and primary intestinal NK-cell lymphoma are rarely reported and poorly characterized in China. In this study, we examined the clinicopathological and molecular features of 38 cases of PITNKL in Chinese patients. Based on these findings, we first classified the patients into an NK-cell group (n=6) and a T-cell group (n=32). In the NK-cell group, the mean age was 37 years. All tumors of the NK-cell group were positive for Epstein-Barr virus encoded mRNA (EBER) in the majority of tumor cells and were polyclonal according to the results of commercial BIOMED-2 TCR gene rearrangement assays. The prognosis in the NK-cell group was significantly worse than that of the T-cell group (p=0.0247). Next, 7 tumors of the T-cell group were considered type II EATL, while 24 were considered peripheral T-cell lymphoma, not otherwise specified (PTCL,NOS). In the type II EATL group, the mean age was 55 years. Typeâ…¡EATL tumor cells from all seven patients were monomorphic, medium sized. The prognosis in the type II EATL group was significantly worse than that of the PTCL, NOS group (p= 0.0181). Multivariate analysis identified NK-cell phenotype, male gender, and CD8 positivity as factors for poor prognosis in our series of PITNKL patients. In conclusion, most cases of PITNKL in China are not associated with celiac disease and could be classified to NK-cell group, type II EATL group, and PTCL, NOS group. Each group has distinctive histopathological features with prognostic significance.