[Misdiagnosis Analysis: 120 Patients with Nasal Extranodal NK/T Cell Lymphoma in Head and Neck]

The Clinicopathological characteristics and the reason of misdiagnosis about nasal extranodal NK/T cell lymphoma in head and neck（ENKTL） are analysised to raise awareness and reduce misdiagnosis. One hundred and twenty patients with ENKTL, diagnosed pathologically in head and neck from May 2010 to April 2018, were analyzed retrospectively. All cases were divided into misdiagnosed group and non-misdiagnosed group according to whether there were misdiagnosis and mistreatment before diagnosis. The differences of clinicopathological characteristics between the two groups before and after diagnosis were compared. The differences of overall survival（OS） between the two groups after treatment were also compared. The misdiagnosis rate of this study was 71.7%, and they were misdiagnosed as sinusitis, nasal polyps, upper respiratory tract infection and so on. On the whole, the 1-year OS, 3-year OS and 5-year OS were 77.8%, 65.9% and 49.3% respectively. There was no significant difference in sex, age, first symptom, initial site, B symptom, superficial lymph node enlargement and weight loss between two groups before diagnosis（>0.05）, however, there were significant differences in relative specific signs, hospital grade and time from first visit to definite diagnosis（<0.05）. The proportion of the high-level hospitals in the first visit hospital was significantly lower than that in the non-misdiagnosed group, while the time from the first visit to the final diagnosis was significantly longer than that in the non-misdiagnosed group. There was no significant difference in international prognostic index（IPI） score, expression of Ki-67, therapeutic schedule, chemotherapy regimen for patients receiving chemotherapy, and radiation dose for patients receiving radiotherapy after diagnosis between the two groups（>0.05）, but there was a significant difference in the clinical stages of Ann Arbor between the two groups（<0.05）. The clinical staging of the misdiagnosed group was later than that of the non-misdiagnosed group. The 1-year OS, 3-year OS and 5-year OS were 73.6%, 59.3% and 43.2% in the misdiagnosed group respectively, and 88.2%, 82.4% and 64.2% in the non-misdiagnosed group respectively. The overall survival rate in the misdiagnosis group was lower than that in the non-misdiagnosed group, and the overall survival time was lower than that in the non-misdiagnosed group. However, there was no significant difference in the overall survival rates between the early stage（Ⅰ and Ⅱ） and the advanced stage（Ⅲ and Ⅳ） of Ann Arbor（>0.05）. The non-specific clinical and the complexity of pathological features of ENKTL in head and neck might cause misdiagnosis, which leads to prolonged time from first visit to definite diagnosis, thus results in disease progression, and ultimately may lead to decreased overall survival rate. To avoid the misdiagnosis and early diagnosis is very important.