Abstract:

Objective According to the latest WHO Classification of tumours  of haematopoietic and  lymphoid tissues in 2008，to observe and analyze the clinical features，morphology and immunophenotypes of primary follicular lymphoma （FL）in the tonsil，and explore its similarities and differences with FL in the lymph node，and contribute to the diagnosis and identified dignosis. Methods The clinical data and diagnostic biopsys of 37 patients with primary FL in the tonsil were reviewed，the expressions of LCA，CD20，CD79a，CD45RO，CD3，CD10，Bcl-6 and Bcl-2 were observed using immunohistochemical staining. Results
The clinical diagnosis before biopsy was 28 cases of  tumor，6 cases of tonsillar cancer and 3 cases of lymphoma patients in 37 patients with  primary FL in  tonsil.The morphological characteristics were similar to nodal FL，there were 4 cases of follicles， 1 case of follicles and diffuse，32 cases of less follicles，no diffuse type.17 cases of grade 1-2，20 cases of grade 3.The LCA and B cell markers，CD20 and CD79a were positive expressed;the CK and T cell markers ，CD45RO and CD3 were negative expressed by immunohistochemical staining.The expression rates of CD10 and Bcl-6 were 43.24% and 86.48%，the co-expression rate of CD10 and Bcl-6 was 37.83%；22 cases expressed the Bcl-2，the positive rate was 59.46%；the expression rates of CD10，Bcl-6，Bcl-2 in low-grade FL and high- grade FL had no statistically significant differences(P>0.05).
The morphology and immunophenotype of 2 cases occurred in children tFL were similar to the new WHO classification with subtypes of the children FL.Conclusion The morphological feature of tonsil FL is similar to lymph node FL， in the biopsy specimens the  less follicular  and the high-grade are the most.The expressions of  germinal center markers and B cell markers are  basically the same as lymph node FL，while the expression rate of Bcl-2 is lower than that of lymph node FL.

Key words: follicular lymphoma； tonsillar neoplasms/pathology