Primary tonsil squamous cell carcinoma:clinicopathological and whole exome sequencing analysis
Purpose To explore the clinicopathological characteristics of tonsil squamous cell carcinoma(TSCC),and to explore the whole exome mutations and tumor mutational bur-den(TMB)in TSCC cases.Methods Ten patients with clini-cally and histopathologically confirmed TSCC and their clinico-pathological characteristics were collected,The expression of CK(AE1/AE3),CK5/6,p63,p40,p16 and Ki67 were meas-ured by two steps of EnVision,and the whole exome sequencing(WES)and TMB were conducted in 3 of them.Results A-mong the 10 patients,there were 6 females and 4 males which aged from 43 to 76 years old.Microscopically,the cancer cells infiltrated into the subdermis of crypts in the form ofnests and irregular cord,accompanied by comedo like necrosis,intercellu-lar bridges,and varying degrees of keratinization.Obvious atyp-ia and mitotic figures were easily seen.Follow-up was available in all cases,ranging from 6 to 45 months.Nine cases had sur-vived.Immunohistochemistry staining showed that all cases were positive for CK(AE1/AE3),CK5/6,p63,p40,and p16 was positively expressed in three cases,and the proliferation index Ki67 ranged from 40%to 90%.The WES of three cases showed that ARID1B and LRP6 were common cancer susceptibility genes,and WDFY4,ZFHX4 exhibited higher mutation rates,which were both 3/3.The TMB analysis showed that one out of three cases was>9 mut/Mb.Conclusion The early symptoms of TSCC are not obvious that lead to easily missed and misdiag-nosed.The WES analyses suggest that WDFY4 and ZFHX4 had a higher mutation rate.The TMB analysis suggests that some TSCC patients may benefit from immunotherapy.