Med Buccle Chir Buccle 2010 2014;20:203-208 SFMBCB, SFCO, 2014 2010 DOI: 10.1051/mc/2014008 10.1051/mc/2009037 www.mc-journl.org Cse report Recurrence chllenge in odontogenic kertocyst vrints, two clinicl cses Belkcem Rouâ *, Sioud Smèh, Touil Dorsf, Aychi Rhm, Selmi Jmil Deprtment of Orl Medicine nd Orl Surgery, University of Dentistry, Avenue Avicenne, 5019 Monstir, Tunisi (Received 29 Septemer 2013, ccepted 15 Decemer 2013) Key words: kertocysts / histology / rdiology / recurrence / tretment Mots clés : kértokystes / histologie / rdiologie / récidive / tritement Astrct Introduction: After rdiculr nd folliculr cysts, odontogenic kertocysts re the third most common cyst of the jws. They cn e unique or multiple when included in sl cell nevus syndrome. The odontogenic kertocyst is known for its high recurrence rte nd locl ggressiveness. It hs een clssified into two histologic vrints: orthokertinized or prkertinized. The im of this report is to highlight the clinicl nd rdiologicl chrcteristics, the histopthologicl fetures, s well s the risk fctors for recurrence of odontogenic kertocysts. Cse report: Two clinicl cses of odontogenic kertocysts with different histologic fetures re reported. Discussion: Rdiologicl nd histologicl fetures, locliztion, extension nd evolutionry spect of the lesion re risk fctors for recurrence, nd therefore hve n impct on the tretment of kertocysts. Through criticl nlysis of the first cse report, the uthors identify therpeutic errors to void, prticulrly when histologic confirmtion of the lesion hs een otined. Résumé Introduction : Après le kyste péripicl et le kyste folliculire, le kértokyste odontogène est le troisième plus fréquent des kystes des mxillires. Il peut être unique ou multiple s il est ssocié à l nevomtose so-cellulire. Le kértokyste un risque élevé de récurrence et une gressivité locle. Il été clssé en deux vriétés histologiques : orthokértinisé ou prkértinisé. Oservtion : Deux cs de kértokystes odontogènes sont décrits sur un pln clinique, rdiologique et histopthologique. Discussion : Le type histologique, l imge rdiologique, l loclistion, l extension et l spect évolutif de l lésion sont des fcteurs de risque de récidive. Ces fcteurs doivent être pris en compte dns l décision thérpeutique. À trvers une nlyse critique du premier cs, les uteurs mettent en exergue les erreurs thérpeutiques à éviter, notmment lorsqu une confirmtion histologique été otenue. Introduction The odontogenic kertocyst ws first descried y Philipsen in 1956 to designte n odontogenic kertocyst with prkertinized epithelil surfce. This lesion hs very ggressive nture nd high recurrence rte, which mkes it distinct from the other kertinized odontogenic cysts. In 2005, the World Helth Orgniztion (WHO) [1] reclssified the kertocyst from cyst to kertocystic odontogenic tumour, which is defined s enign, uni- or multi-cystic, introsseous tumour of odontogenic origin, with prkertinized strtified squmous epithelium, nd ggressive ehviour. Before this clssifiction, the odontogenic kertocyst ws clssified into two histologic vrints: orthokertinized nd prkertinized. Afterwrds, reserch showed tht the orthokertinized vrint not only lcks the typicl chrcteristics of the prkertinized one, ut lso hs different iologicl chrcteristics nd consequently much lower recurrence rte. Rdiologicl nd histologicl fetures, the lesion topogrphy nd numerous other fetures cn constitute risk fctors of recurrence. Therefore, they should guide the therpeutic choice. Tking these dt into considertion nd sed on two clinicl cse reports, the im of this rticle is to report the min chrcteristics of this lesion nd their implictions on tretment, nd lso to highlight some therpeutic errors to void through criticl ssessment of the first cse report. * Correspondence: rouelkcem@gmil.com Article pulié pr EDP Sciences 203
Fig. 1. : extr-orl clinicl spect, : intr-orl clinicl spect. Fig. 1. : spect clinique extr-orl, : spect clinique intr-orl. c Fig. 2. Rdiologic spect of the lesion. : pnormic rdiogrph, : sgittl computed tomogrphy reconstruction, c: olique coronl reconstruction showing the sence of invsion of the mndiulr cnl nd the perfortion of the lingul cortex (rrow). Fig. 2. Aspect rdiologique de l lésion. : rdiogrphie pnormique, : reconstruction scnogrphique sgittle, c : reconstruction coronle olique montrnt l sence d invsion du cnl mndiulire et l perfortion de l corticle lingule (flèche). Clinicl cse reports Cse report 1: A 20-yer-old ptient with non-contriutory medicl nd surgicl history ws referred for the ppernce of right lower fcil cellulitis, developing one week erlier. The dentist prescried ntiiotics nd non-steroidl nti-inflmmtories for week tht resulted in no improvement. On initil exmintion in our deprtment, pinful cheek tumefction nd limited mouth opening were noted. Introrl exmintion reveled purulent dischrge from the retromolr region nd second-degree moility [2] (horizontl moility exceeding 1 mm) of the second mndiulr molr, which tested positive for vitlity (ethyl chloride vitlity test) (Fig. 1). Plption of the lingul nd vestiulr one did not revel ny deformity. A well-defined rdiolucent multiloculr imge with peripherl one condenstion nd polycyclic contours spreding to the posterior prt nd the right mndiulr ngle nd voiding the condyle ws oserved on the pnormic rdiogrph. Considering the spect of the lesion, the possile dignoses were odontogenic kertocystic tumour or melolstom. Computed tomogrphy reveled hypodense imge reking the lingul cortex with dense liquid content (Fig. 2). The initil tretment consisted in simple enucletion of the lesion under generl nesthesi without extrction of tooth 47. Histologicl exmintion concluded tht n odontogenic kertocystic tumour of prkertosic type ws present (Fig. 3). However, recurrence ws noted four months lter nd revision of the cystic cvity ws performed with more thorough curettge of cystic wlls, without extrction of the lst inferior molr. The lesion remined stle for three yers fter the second surgicl intervention (Fig. 4) Cse report 2: A 50-yer-old ptient without ny medicl history ws referred for incidentl discovery of rdiolucent mndiulr imge locted t the pices of the lower incisors (Fig. 5). Only the right centrl incisor rected negtively to the vitlity test. Pnormic rdiogrphic exmintion reveled uniloculr rdiolucency with well-limited corticted orders locted t the pices of the resored inferior incisors nd cnines (Fig. 6). Following these findings, peripicl cyst, kertocyst, n essentil one cyst or n melolstom were suspected. First, the ptient underwent endodontic tretment of the necrotic tooth followed y surgicl enucletion of the cyst. Finlly, incisors nd mndiulr cnines were extrcted due to insufficient one support nd the intr-opertive presence of kertine (Fig. 7). Histologicl exmintion concluded 204
Med Buccle Chir Buccle 2014;20:203-208 Fig. 3. Histologicl spect: : t low mgnifiction (x10), : t high mgnifiction (x50). The cyst wll is lined with prkertinized squmous epithelium (yellow rrow); Light is filled with kertin lmelle (lck rrow). Fig. 3. Aspect histologique : : à file grossissement (x10), : à fort grossissement (x50). L proi kystique est entourée pr un épithélium squmeux prkértinisé (flèche june) ; l lumière est remplie de lmelles de kértine (flèche noire). Fig. 5. Intr-orl clinicl spect. Fig. 5. Aspect clinique intr-orl. Fig. 6. Rdiologic spect of the lesion: pnormic rdiogrphy showing uniloculr rdiolucency with well-limited corticted order. Fig. 6. Aspect rdiologique de l lésion : rdiogrphie pnormique montrnt une rdioclrté ordée pr un liseré d ostéocondenstion. Fig. 4. After three yers of follow-up; pnormic rdiogrph: reossifiction signs nd the persistence of rdiolucency surrounding the roots of the tooth (47). Fig. 4. Rdiogrphie pnormique près trois ns : des signes de réossifiction vec persistnce d une rdioclrté entournt les rcines de l 47. tht n orthokertinized kertocyst ws present (Fig. 8). The lesion ws stle for three yers fter surgery (Fig. 9) Discussion The odontogenic kertocyst or epidermoid cyst s it ws previously clled, rises from the cell rests of dentl lmin or prolifertion of epithelil rests [3]. Its frequency mong cysts of the jws is 10 to 20% [4]. It is more common in the second nd third decdes of life nd it cn pper erlier when it is ssocited with sl cell nevus syndrome. The mjority of these cysts re found in the scending rmus of the mndile [5]. Histologiclly, the WHO designted two different vrints of odontogenic kertocyst in 1992, n orthokertinized nd prkertinized one. The prkertinized form, often found in the sl cell nevus syndrome, consists in sl lyer mde Fig. 7. Intropertive spect of the lesion: lesion which tends to externlize with persistence of fine one wll without dherence to periosteum, presence of kertin intropertively. : After flp relese, : fter enucletion of the lesion. Fig. 7. Aspect per-opértoire de l lésion : tendnce à l extérioristion vec persistnce d une fine coque osseuse sns dhérence u périoste, présence de kértine. : près décollement du lmeu, : près énuclétion de l lésion. of cuic or cylindricl cells lcking cnthosis nd rete ridge prolifertion. It is covered y five to eight lyers of squmous epithelium lining. The epithelium is chrcterized y wvy or corrugted prkertinized surfce lyer. Some signs of dysplsi my e oserved. The sl lyer of the tumour might e udding into the supporting connective tissue, forming dughter cysts t the periphery. If inflmmtion occurs, the firous cpsule in the wll of the connective tissue thickens. 205
Fig. 8. Histologicl spect: cystic wll lined y n orthokertosic epithelium (rrow). Fig. 8. Aspect histologique : l proi kystique est entourée pr un épithélium orthokértinisé (flèche). In ddition, it my cuse ulcertion of the epithelium, which cquires well-developed ridges, wheres the kertiniztion tends to dispper. This cpsule cn contin dystrophic clcifictions or smll frgments of crtilge of unknown origin [6]. In contrst, the orthokertinized vrint displys squmous sl lyer, prominent grnulr lyer, orthokertiniztion, s well s high tendency to spred kertine in the cyst [7]. Symptomtic kertocysts present inflmmtory signs on histology. This infiltrte cuses cystic epithelium metplsi giving rise to the formtion of strtified non-kertinized epithelium, which my led in turn to difficulty in dignosis or flse negtive. The reclssifiction of the WHO [1] in 2005 cst dout on the cystic nture of the prkertinized type tht ws renmed kertocystic odontogenic tumour ecuse mny uthors found tht this form hd higher mitotic ctivity nd diminishes tumour suppressor genes [6]. The orthokertinized vrint ecme prt of the odontogenic cysts, which underwent metplstic orthokertinistion, involving the gingivl cyst, the residul cyst, the primordil cyst, dentigerous cyst nd periodontl cyst. This reclssifiction ws not universlly ccepted nd thus the tretment remins controversil with reltively high recurrence risk. Guy Le Toux [8] reports recurrence rte etween 3% nd 62%, ssocited with mny fctors: the histologic nture, the rdiologic imge, the topogrphy nd the extension of the lesion (corticl perfortion). Its primry evolutive spect or recurrence re fctors tht hve to e tken into considertion efore proceeding to surgicl tretment. Dyhimi [9] compred the iologicl chrcteristics of prkertinized odontogenic kertocysts with those of orthokertinized odontogenic cysts, including the orthokertinized kertocyst, using P53 nd TGF-lph (Tumour-Growth- Fctor-lph) s mrkers. He concluded tht these proteins re Fig. 9. Follow-up pnormic rdiogrph showing reossifiction signs in the mndiulr nterior region. Fig. 9. Rdiogrphie pnormique de contrôle montrnt des signes de réossifiction de l région mndiulire ntérieure. more frequently found in odontogenic kertocystic tumours. This cn explin the ggressive nture nd the recurrence tendency noted in the first cse report. On the other hnd, the orthokertosic forms re treted like the other cysts of the jws. A recurrence rte of 42.6% is reported in the literture for the prkertosic vrint compred to 2.26% for the orthokertosic form [6]. Rdiologic imges of kertocysts re either uniloculr or multiloculr, including multiple rdiolucent imges tht re well defined nd surrounded y peripherl one condenstion with smooth or polycyclic orders. Singh [10] studied the reltionship etween the rdiogrphic spect nd the prolifertion of epithelil cells using prolifertion mrkers (PCNA: proliferting cellulr nucler ntigen). He concluded tht uniloculr imges compred to multiloculr imges displyed lower prolifertive potentil; therefore, it should not e treted s tumour. The rdiologic spect in the second cse ws uniloculr. After conservtive tretment, it did not show signs of recurrence fter three-yer follow-up, while the multiloculr imge of the first cse report needed two interventions efore eing stilized, thus confirming Singh s suggestion. The uthor nd others [11] suggest tht the inflmmtion increses mitotic ctivity of the multiloculr lesion. The recurrence tht occurred in the first cse report cn e explined y inflmmtion nd secondry infection. The topogrphy of the lesion seems to e recurrence risk fctor. The ngle nd rmus lesions re more recurrent: this could e due to difficulty of ccess during resection, minly for the multiloculr forms [12]. Kertocyst infection my lso led to higher rte of recurrence [10, 11]. Presence of stellite cysts t the surfce epithelium, corticl perfortion nd extension to soft tissues, were ssocited with recurrence rte of 60% in retrospective study [12]. Eventully, the condition of the tumour excision is mjor prognostic fctor. Enucletion of single unit is less recurrent thn tht of severl 206
frgments. Lesions ssocited with Gorlin-Goltz syndrome require more ggressive tretment ecuse of higher recurrence risk [13]. All teeth djcent to the lesion should e extrcted s they my e source of recurrence risk. In the first cse report, the second mndiulr molr ws not extrcted even though its roots reched into the tumour mss; this could e the source of the second recurrence. Follow-up pnormic rdiogrph reveled persistence of rdiolucency surrounding the teeth roots. Surgicl tretment should e prepred y complete clinicl nd rdiogrphic exmintion (computed tomogrphy), nd followed y two clinicl nd rdiologic follow-ups per yer. Different surgicl techniques hve een suggested for the tretment of kertocysts nd the most pproprite tretment remins suject of controversy. Aggressive tretment, such s ostectomy, is necessry in cses ssocited with corticl effrction, coronl invsion, soft tissue invsion, multirecurrent kertocyst, n melolstic grft or mlign trnsformtion. Complete enucletion is recommended for introsseous lesions without corticl rupture. Enucletion ssocited with mrginl resection using ur is done if the split is difficult. Periostectomy is involved if the lesion dheres to the periostel elevtor. A posterior mndiulr loction necessittes enucletion with n excision extended to the djcent mucos to limit the recurrence risk tht my come from the orl mucos. "Mrsupiliztion" is etter suited for children with mixed denture in order to preserve the permnent teeth uds nd lso for lesions tht resored nsl wlls, sinus or tht develop close to the lower lveolr nerve. Decompression ssocited with lter enucletion is recommended for the infected lesions to reduce their volume nd thin their lining [6, 8, 14, 15]. Co [16], in his clinicl study of lrge mndiulr odontogenic kertocystic tumours in dolescents treted y decompression, found no recurrence over period of 1 to 5 yers fter opertion. Some uthors [17] conducted morphometric nlysis of the epithelil lining nd firous cpsule in histologicl sections of odontogenic kertocystic tumours efore nd fter decompression. They reported considerle thickening of the tumour s firous cpsule. This chnge fcilittes the surgicl procedure, which my explin the lower level of recurrence. Some limits of these cse reports must e rised. In the first cse, rdiologic fetures suggested tht this lesion ws n odontogenic kertocystic or n melolstom nd it spred to the mndile ngle, the scending rmus, nd prt of the horizontl right mndiulr rnch nd the cornoid process. These two tumours hve high recurrence risk (possily more thn 80% for melolstom [18]). Moreover, other fctors of poor prognosis re present: the multiloculr nture of the imge, corticl reking nd invsion of soft tissues. These conditions justified rdicl tretment. However, the surgicl tretment involved simple enucletion without extrction of tooth 47 nd without mrginl resection of the mndiulr rnch, which ws non-dpted therpy ccording to the literture. During the second surgery, lthough the histopthologic result ws in fvour of prkertinized type, the surgeon pplied the sme surgicl tretment (simple enucletion) without removl of the second molr. The lesion ws cliniclly silent for three yers. But, follow-up pnormic rdiogrph showed the persistence of rdiolucency surrounding the roots of tooth 47. The dignosis of perirdiculr condition ws ruled out s the tooth responded positively to the vitlity test. Periodontl proing did not revel ny distl periodontl pocket. This could suggest tht the peri-rdiculr imge corresponded to tumorl tissue incompletely eliminted. This conservtive tretment voided performing lrge one resection ut the risk of recurrence of the lesion ws still present. This ptient should hve hd tooth 47 extrcted nd curettge of remining soft tissues. Then, she should hve een closely monitored to dignose ny recurrence erly. The sence of recurrence in the second cse confirms the literture dt nd justifies our conservtive pproch (Fig. 9). Tretment of odontogenic kertocysts depends on their clinicl nd rdiologic fetures. Teeth in reltion with the lesion should e extrcted s they my e the source of recurrence. To prevent the risk of mlignnt trnsformtion [19] or n melolstic grft nd the recurrence prolem, strict follow-up is necessry especilly for kertocystic odontogenic tumours. Conflicts of interests: none declred References 1. Brnes L, Eveson J, Reichrt P, Sidrnsky D. World Helth Orgniztion Clssifiction of Tumours. Pthology nd Genetics of Hed nd Neck Tumours. IARC Press: 2005;306-7. 2. Lindhe J, Nymn S. Clinicl trils in periodontl therpy. J Periodontl Res 1987;22:217-21. 3. Thesleff I. Epithelil cell rests of Mlssez ind epiderml growth fctor intensely. 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