Clinical Investigation Of The Classification System1 Based On The Origin Of Nasal Inverted Papilloma

BackgroundNasa1 inverted papilloma(NIP) is a primary benign epithelial tumor.Its share of all tumorous lesions of the nose and paranasal sinuses is 0.5-4%.NIP is a benign tumor,but it has a high recurrence rate.The frequency of recurrence after surgical removal is reported as 0-75%.Complete surgical removal is the first option for the treatment of NIP.Removal should be complete to avoid recurrence.A variety of surgical techniques has been developed.Radical transfacial approaches like lateral rhinotomy,minimally invasive transnasal endoscopic techniques,and anything in between including midface degloving procedures are in use for the treatment of NIP.Cannady found that the recurrence rate is 12.2%,based on a statistics of 445 NIP patients who treated with transnasal endoscopic techniques. That is to say,the recurrence rate with transnasal endoscopic techniques correspond to the recurrence rate with lateral rhinotomy.The aim of surgery must always be the eradication of the disease at the first attempt.The recurrence rate increases markedly if there was inadequate removal in the first place.Another important goal of surgery is to have an anatomically clear situation postoperatively allowing the site to be properly monitored at follow-up.Staging has become essential to achieve the optimal and less-morbid surgical treatment with NIP of varying extent.There is still no universal staging system of NIP to plan surgery and/or evaluate results.Several attempts have been made to develop a uniform staging system for grading NIP.All previous staging systems of NIP depended on either size and/or extent of the tumor.1.The nasal/sinus component of the common TNM staging system for malignant neoplasm was suggested for NIP.This classification was applied to the histological benign NIP because its clinical behavior often resembles that of malignant tumors:T1:one distinct intranasal anatomic site involvedT2:two adjacent intranasal sites involvedT3:extension into the paranasal sinusesT4:extension of tumor beyond the confines of the nasal cavity and paranasal sinuses(e.g.orbit,nasopharynx,dura,or soft tissue of nose or face)2.In 2000,Krouse developed a staging system based on the extent of tumor involvement depending on endoscopic,CT,and MRI examinations.The importance of this classification is because of the impact of the portion or portions of the antrum involved and/or extra sinonasal extensions on surgical plan:T1:tumor totally confined to the nasal cavity;the tumor can be localized to one wall of the nasal cavity or can be extensive within the nasal cavityT2:tumor limited to the medial and superior portions of the maxillary sinus and/or involving the ethmoid sinus,with or without involvement of the nasal cavityT3:tumor involving the lateral inferior;anterior;or posterior walls of the maxillary sinus,the sphenoid sinus,and/or the frontal sinus,with or without involvement of the ethmoid sinuses,or the nasal cavityT4:tumor extending outside the confines of the nose and/or paranasal sinuses to involve adjacent,contiguous structures(e.g.,the orbit,intracranial compartment,or the pterygomaxillary space)Nowadays,Krouse's system is used to be the standard of the classification for NIP at home.However,some people abroad believed that the origin of NIP is more important than the extent.Kamel introduced a new classification system of IP based on the origin of the lesion in2005:TypeⅠ:originates from the nasal septum or the lateral nasal wallTypeⅡ:originates from the maxillary sinusWe believe that the classification system of NIP based on the origin of the lesion introduced by Kamel can be more significant in planning surgery and evaluating results.So,we performed a retrospective study.ObjectiveTo investigate the clinical classification of NIP and to show how to use this classification in planning surgery and evaluating results.Subjects and Method1.SubjectsForty -seven cases of NIP patients underwent curative surgery in our hospital from 1997 to 2006.There were 34 men and 13 women whose ages ranged between 27 and 78 years. There were 16 right- and 31 left-sided lesions.Eleven patients(23.4%) had a history of previous nasal surgery.Some proved to be the nature of the disease by biopsy before surgery(typeⅠ:18;typeⅡ:7).All proved to be the nature of the disease by biopsy after surgery.We did not find carcinoma in 47 cases.2.Method2.1 We performed a retrospective study with forty -seven cases of NIP patients.1) Origin: The lesions were classified into typeⅠ(28 cases),originating from the nasal septum or lateral nasal wall(LNW),and typeⅡ(19 cases),originating from the maxillary sinus.We confirmed the origin of the lesion before surgery:typeⅠ21eases, typeⅡ11 cases.2) Course of disease:This course of disease ranged between 2 months and 10 years(average course, 25 months,and median course,18 months).This course of TypeⅠranged between 2 months and 8 years(average course,21 months,and median course,16 months).This course of TypeⅡranged between 6 months and 10 years(average course,31 months, and median course,24 months).3) Symptom:The main complaint was unilateral nasal obstruction(typeⅠ:20;typeⅡ:10) and epitasis(typeⅠ:23;typeⅡ:13).Rarely occurring symptoms are headache rhinorrhoea,and so on.4) Extent:Ethmoid sinuses were involved in 19 cases.Maxillary sinuses were involved in 23cases.Sphenoid sinuses were involved in one case.Frontal sinuses were involved in 2 cases.5) Modus operandi:We performed with conservative transnasal endoscopic excision(28 cases) in TypeⅠand with performed conservative transnasal endoscopic excision(4 cases), radical transnasal endoscopic medial maxillectomy(4 cases),combined approach(8 cases),Lateral rhinotomy(3 cases,before 2000).6) Recurrence rate:In Type I recurrence rate was 7.1%(2/28).and 10.5%(2/19) in TypeⅡ,8.5% (4/47) in all cases.Recurrence rate was 2.8%(1/36) after endoscopic surgery in primary cases of both types,and 27.3%(3/11) in secondary cases.2.2 Classification1) TypeⅠ:originates from the nasal septum or the lateral nasal wall2) TypeⅡ:originates from the maxillary sinus2.3 Follow-upFollow-up periods ranged from 1 to 8 years.No patients were lost to follow-up.2.4 Statistical analysis:SPSS 11.5 statistical soft was used.The compared of two groups was tested by chi-square test(correction for continuity) and Fisher's exact test.Results1.There were not significant difference in age and sex between TypeⅠand TypeⅡ.2.Some proved to be the nature of the disease by biopsy before surgery(typeⅠ: 18/28,64.3%;type II:7/19,36.8%).That is to say,TypeⅠcan be found and be biopsy in earlier period,TypeⅡis on the opposite side.3.The course of TypeⅠranged between 2 months and 8 years(average course21 months,and median course,16 months).The course of TypeⅡranged between 6 months and 10 years(average course,31 months,and median course,24 months).It means that TypeⅡlocate extremely and results in late diagnosis.4.The main complaint was unilateral nasal obstruction(TypeⅠ:20/28,71.4%; TypeⅡ:10/19,52.6%) and epitasis(TypeⅠ:23/28,82.1%;TypeⅡ:13/19,68.4%). Lesions arising from the nasal septum or LNW presenting the nasal cavity resulting in nasal obstruction and early diagnosis while the lesion is relatively small and limited. Tumors originating from the maxillary sinus give vague symptoms and result in late diagnosis while the lesion is large and extensive.5.With recent advances in transnasal endoscopic sinus surgery and CT/MRI, NIP regardless of its size,location,and/or extent could be traced to its origin.In typeⅠ,the origin of the lesion was localized in most of the cases(25 cases,89.3%) and pedicled in 17 cases(60.7%).In typeⅡ,the origins were wide and diffuse in all cases (19 cases,100%).All cases were unilateral with no secondary attachment and/or multicentricity.6.In TypeⅡ,medial wall was involved in all cases,inferior involved in 15 cases,anterior involved in 7 cases,lateral involved in 7 cases,posterior involved in 9 cases,superior involved in 1 cases.7.In most case(76.6%),tumors were found in nose cavity(Type I,85.7%, TypeⅡ,63.2%).In TypeⅠ,maxillary sinus was involved in four cases that were origined from lateral nasal wall.Nasolacrimal duct was involved in 52.6%TypeⅡ.The extension of tumor beyond the confines of the nasal cavity and paranasal sinuses(e.g.,orbit,nasopharynx,dura,or soft tissue of nose or face) were not found in all cases.8.We performed with conservative transnasal endoscopic excision(28 cases) in Type I and with performed conservative transnasal endoscopic excision(4 cases), radical transnasal endoscopic medial maxillectomy(4 cases),combined approach(8 cases),Lateral rhinotomy(3 cases,before 2000).9.In TypeⅠrecurrence was 7.1%(2/28).and 10.5%(2/19) in TypeⅡ,8.5% (4/47) in all cases.The recurrence of TypeⅠand TypeⅡwere compared:a=0.05,v=1,1＜T(1.6)＜5,n(47)＞40,X~2C =0.000＜3.84,The difference was not statistically significant(chi-square test,correction for continuity).Tumors originating from the maxillary sinus(TypeⅡ) give vague symptoms and result in late diagnosis while the lesion is large and extensive.However,the difference was not statistically significant between TypeⅠand TypeⅡ.So,it proves that this classification has a role in planning surgery and evaluating results. 10.Recurrence was 2.8%(1/36) after endoscopic surgery in primary cases of both types,and 27.3%(3/11) in secondary cases.The recurrence of primary cases and secondary cases were compared:a=0.05,v=1,T(0.9)＜1,n(47)＞40,P_c=0.035＜0.05.The difference was statistically significant(Fisher's exact test).The secondary cases were deal with more difficult than the primary cases during surgery.ConclusionWith nasal endoscopy and CT/MRI,we can trace the origin of NIP.The classification system based on the origin of NIP is helpful in planning surgery and evaluating results.Lesions arising from the nasa1 septum or LNW present in the nasal cavity resulting in nasal obstruction and early diagnosis while the lesion is relatively small and limited.Tumors originating from the maxillary sinus give vague symptoms and result in late diagnosis while the lesion is large and extensive.We performed with conservative transnasal endoscopic excision in TypeⅠand with performed radical transnasal endoscopic medial maxillectomy and combined approach in TypeⅡ.The difference was not statistically significant in the recurrence of Type I and TypeⅡ.So, it proves that this Kamel's classification has a role in planning surgery and evaluating results.Through carcinoma in patients with NIP did not involve in the classification,we still believe that Kamel's classification is worthy to be spread.