Expect the unexpected – A rare case of Orthokeratinized Odontogenic Cyst and its surgical management

Orthokeratinized Odontogenic Cyst (OOC) is a rare, developmental odontogenic cyst of the dental lamina. It was initially defined as the uncommon orthokeratinized variant of the Odontogenic Keratocyst (OKC), until the World Health Organization’s (WHO’s) classification in 2005 and 2017, where it was separated from the Keratocystic Odontogenic Tumor (KCOT) and has been included as a separate entity from the category of developmental odontogenic cysts respectively. It presents as a unilocular radiolucent lesion involving the posterior mandible and is frequently related to impacted teeth, often similar to other odontogenic cysts. Due to low local aggressiveness and less proliferative activity, it has to be differentiated from the other cysts in terms of surgical management. Here we report a rare case of OOC involving the maxilla along with an impacted canine and discuss the surgical management and why a secondary surgical intervention is unnecessary.

P53 Protein Expression in Epithelial Lining of Odontogenic Cysts: An Immunohistochemical Descriptive Case Study

OBJECTIVES: The current study was conducted to analyze immunohistochemical appearance of P53 protein in odontogenic cysts. METHODOLOGY: Thirty paraffin blocks of confirmed case were prepared to investigate the immunohistochemical appearance of P53 protein. RESULTS: Sixteen out of thirty odontogenic cysts (53.3%) showed P53, four out of ten dentigerous cyst (40%) had P53, twelve out of fifteen odontogenic keratocysts (80%) expressed P53 while none of the five radicular cysts (0%) showed P53 protein. CONCLUSION: Reclassification of OKC as keratocystic odontogenic tumor was supported by the present study and its findings.

A Rare Odontogenic Cyst in an Uncommon Area: Case Report and Review of the Literature

Objective Orthokeratinized odontogenic cyst is a rare developmental odontogenic cyst of the jaws. It is a less aggressive intraosseous cyst identified by an orthokeratinized epithelium. Case Report A 50-year-old male patient with the chief complaint of swelling in the anterior part of his face, and, intraorally, there was diffuse swelling in the palatal cortex. On panoramic radiography, there was a well-defined unilocular radiolucency on the right side of the maxilla and palatal cortical expansion, and thinning of the buccal and palatal cortexes was observed. The histopathological examination revealed a pathologic cyst that was lined by a thick orthokeratinized epithelium. Therefore, the diagnosis was orthokeratinized odontogenic cyst. Conclusion The orthokeratinized odontogenic cyst displays characteristic clinical, histopathological, and biological features that differ significantly from those of keratocystic odontogenic tumor (KCOT), but it has a better prognosis and lower recurrence rate. Thus, other radiolucent lesions of the jaws, including keratocystic odontogenic tumor (KCOT), must be considered in the differential diagnosis.

Evaluation of the Connective Tissue Wall in Sporadic Cases of Keratocystic Odontogenic Tumor (KCOT) Using MMP-9 and Confocal Microscopy: A Retrospective Study

Background: Keratocystic odontogenic tumor (KCOT) is an odontogenic lesion which manifests distinct biological behavior. Predominant studies in KCOT attribute this behavior to high epithelial proliferative capacity. Besides, a few studies facet loosely arranged collagen can contribute to the behavior of KCOT. Matrix metalloproteinases (MMP) are enzymes that degrade extracellular matrix components under both physiologic and pathologic conditions. The loosely arranged collagen in connective tissue wall of KCOT could be related to the degree of MMP-9 expression. Aim: To evaluate the arrangement of collagen fibers along with immunoexpression of MMP-9 and to relate to its neoplastic biologic behavior in sporadic cases of KCOT. Materials and Methods: KCOT ( n = 23) and dentigerous cyst (DC) ( n = 15) samples were processed for the following techniques: Masson’s trichrome stain for light microscopy, PMA-PSR stain for confocal microscopy, and MMP-9 for immunohistochemistry. Results: In Masson’s trichrome analysis, correlation of collagen fiber arrangement in the deeper regions with color intensity for KCOT was found to be statistically significant ( P = .033). In confocal microscopy, there was no difference between intensities in KCOT ( P = .990) and DC ( P = .233), respectively. The immunoexpression of MMP-9 in the connective tissue wall of DC (73.3%) was relatively higher than that of KCOT (60.8%). However, on comparison between KCOT and DC in the presence of inflammation, the immunoexpression of MMP-9 was higher in DC (100%) than KCOT (69.9%) and was statistically significant ( P = .028). Conclusion: It was concluded that the loose connective tissue wall in KCOT is because of the inherent nature of the lesion that could facilitate its biologic behavior. If inflammation is present, this could further aggravate the tumorigenic behavior.

Queratocisto odontogênico em mandíbula: relato de caso

Introdução: O queratocisto odontogênico é por definição um cisto de desenvolvimento que apresenta caráter agressivo afetando o complexo bucomaxilofacial. Tendo em vista que muitas vezes são assintomáticos, o seu diagnóstico normalmente é obtido através de exames radiográficos de rotina. Objetivo: apresentar um caso clínico referente ao diagnóstico e tratamento de um queratocisto odontogênico em região posterior de mandíbula. Caso clínico: Paciente do sexo feminino, normosistemica, feoderma. Observou-se aumento de volume extraoral, lado direito da face em região de ângulo mandibular. Ao exame radiografico periapical, observou-se uma imagem radiolúcida, bem delimitada, unilocular, associada ao dente 47. Ao exame físico intraoral, observou-se abaulamento ósseo na região do referido dente. Foi então solicitada uma tomografia computadorizada, na qual foi detectada extensa lesão óssea expansiva em ramo mandibular direito. Realizou-se uma punção aspirativa local, detectando presença de conteúdo líquido. Primeiramente foi realizada uma biópsia incisional com instalação de dispositivo descompressivo. O laudo histopatológico foi de cisto odontogênico inflamatório. O dispositivo de descompressão permaneceu por 9 meses, apresentando uma diminuição significativa da lesão. Foi realizada então, a enucleação da lesão remanescente, associado a exodontia dos dentes 47 e 48 e enviado material para histopatológico, que dessa vez, confirmou diagnóstico de queratocisto odontogênico. Ao exame de imagem pós-operatório de 6 meses, observou-se formação óssea completa sem sinais de recidiva. Conclusão: O tratamento proposto se mostrou eficaz no tratamento do queratocisto odontogênico, o acompanhamento com exames de imagem é de extrema importância, tendo em vista a possibilidade de recidiva. Descritores: Recidiva; Cistos Odontogênicos; Patologia Bucal. Referências Freitas DA, Veloso DA, Santos ALD, Freitas VA. Ceratocistoodontogênico maxilar: relato de caso clínico. RGO Rev Gauch Odontol. 2015;63(4):484-88. Antunes AA, Avelar RL, Santos TS, Andrade ESS, Dourado E. Tumor odontogênico ceratocístico: análise de 69 casos/ Keratocystic odontogenic tumor: analysisof 69 cases. Rev bras cir cabeça pescoço. 2007;36(2):80-2. Moura BS, Cavalcante MA, Hespanhol W. Tumor odontogênico ceratocístico. Rev Col Bras Cir. 2016;43(6):466-71. Wright JM, Vered M. Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumors. Head Neck Pathol. 2017;11(1):68-77. Neville BW, Allen CM, Damm DD, Chi A. oral and maxillofacial pathology, 4. ed. Rio de Janeiro: Elsevier; 2016. Aciole GTS, Santos MAM, Aciole JMS, Ribeiro Neto N, Pinheiro, ALB. Tumor odontogênicoqueratocistorecidivante: tratamento cirúrgico conservador ou radical? Relato de caso clínico. Rev cir traumatol buco-maxilo-fac. 2010;10(1):43-8. Hupp JR. Cirurgia oral e maxilofacial contemporânea. 6. ed. Rio de Janeiro: Elsevier, 2015. Marques JAF, Neves, JL, Alencar, DA, Lemos IM, Marques LC. Ceratocisto Odontogênico: relato de caso. Sitientibus. 2006;34(1):59-69. Conceição ACA, Santos AM, Santos GP, Almeida AJ, Dias AMN, Mainenti P. Tumor odontogênico queratocístico: atualidades. RIEE. 2012;4(1): 29-35. Pereira CCS, Carvalho ACG de S, Jardim ECG, Shinohara EH, Garcia Júnior IR. Tumor Odontogênico Queratocístico e considerações diagnósticas. RBCS. 2012;10(32):73-9. Balmick S, Hespanhol W, Cavalcante MAA, Gandelmann IHA. Recidiva do Tumor Odontogênico Ceratocístico: Análise retrospectiva de 10 anos. Rev cir traumatol buco-maxilo-fac. 2011;11(1):85-91. Borghesi A, Nardi C, Giannitto C, Tironi A, Maroldi R, Di Bartolomeo F, Preda L. Odontogenic keratocyst: imaging features of a benign lesion with an aggressive behaviour. Insights Imaging. 2018;9(5):883-97. Johnson NR, Batstone MD, Savage NW. Management and recurrence of keratocystic odontogenic tumor: a systematic review. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013;116(4):e271-76. Araújo S, Oliveira LKR, Pigatti FM, Mayrink G. Queratocisto odontogênico em região anterior da maxila: relato de caso. HU rev. 2019;45(1):82-6. Oliveira Júnior HCC, Chaves Netto HDM, Rodrigues MTV, Pinto JMV, Nóia CF. Descompressão cirúrgica no tratamento de lesões císticas da cavidade oral. Rev cir traumatol buco-maxilo-fac. 2014;14(1):15-20. Pazdera J, Kolar Z, Zboril V, Tvrdy P, Pink R. Odontogenic keratocysts/keratocystic odontogenic tumours: biological characteristics, clinical manifestation and treatment. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2014;158(2):170-74.

Odontogenic Keratocyst

A 37-year-old woman consulted for a slow-growing mass of one-year duration on the left side of the mandible with associated tooth mobility. Clinical examination showed buccal expansion along the left hemi-mandible from the mid-body to the molar-ramus region with associated mobility and displacement of the pre-molar and molar teeth. Radiographs showed a well-defined unilocular radiolucency with root resorption of the overlying teeth. Decompression and unroofing of the cystic lesion was performed. Received in the surgical pathology laboratory were several gray-white rubbery to focally gritty tissue fragments with an aggregate diameter of 1 cm. Histopathologic examination shows a fibrocollagenous cyst wall lined by a fairly thin and flat stratified squamous epithelium without rete ridges. (Figure 1) The epithelium is parakeratinized with a wavy, corrugated surface while the basal layer is cuboidal and quite distinct with hyperchromatic nuclei. (Figure 2) Based on these features, we signed the case out as odontogenic keratocyst (OKC). Odontogenic keratocysts are the third most common cysts of the gnathic bones, comprising up to 11% of all odontogenic cysts, and most frequently occurring in the second to third decades of life.1,2 The vast majority of cases occur in the mandible particularly in the posterior segments of the body and the ramus. They typically present as fairly large unilocular radiolucencies with displacement of adjacent or overlying teeth.1 If associated with an impacted tooth the radiograph may mimic that of a dentigerous cyst.2 Microscopically, the parakeratinized epithelium without rete ridges, and with a corrugated luminal surface and a prominent cuboidal basal layer are distinctive features that enable recognition and diagnosis.1,2,3 Occasionally, smaller “satellite” or “daughter” cysts may be seen within the underlying supporting stroma, sometimes budding off from the basal layer. Most are unilocular although multilocular examples are encountered occasionally.1 Secondary inflammation may render these diagnostic features unrecognizable and non-specific.2 Morphologic differential diagnoses include other odontogenic cysts and unicystic ameloblastoma. The corrugated and parakeratinized epithelial surface is sufficiently consistent to allow recognition of an OKC over other odontogenic cysts, while the absence of a stellate reticulum and reverse nuclear polarization will not favor the latter diagnosis.2,3 Odontogenic keratocysts are developmental in origin arising from remnants of the dental lamina. Mutations in the PTCH1 gene have been identified in cases associated with the naevoid basal cell carcinoma syndrome as well as in non-syndromic or sporadic cases.1,3 These genetic alterations were once the basis for proposing a neoplastic nature for OKCs and thus the nomenclature “keratocystic odontogenic tumor” was for a time adopted as the preferred name for the lesion.3,4 Presently, it is felt there is not yet enough evidence to support a neoplastic origin and hence the latest WHO classification reverts back to OKC as the appropriate term.1 Sekhar et al. gives a good review of the evolution of the nomenclature for this lesion.3 Treatments range from conservative enucleation to surgical resection via peripheral osteotomy.5 Reported recurrences vary in the literature ranging from less than 2% of resected cases up to 28% for conservatively managed cases.1,5 These are either ascribed to incomplete removal or to the previously mentioned satellite cysts - the latter being a feature associated with OKCs that are in the setting of the naevoid basal cell carcinoma syndrome.1,2,3 Thus, long term follow-up is recommended.5 Malignant transformation, though reported, is distinctly rare.2

Keratocystic Odontogenic Tumor with ameloblastomatic changes mimicking dentigerous cyst : An unusual case report

The OdontogenicKeratocystic (OKC) is a developmental cyst derived from the remanants (rest) of the dental lamina with a peculiar biological behavior. Many attempts have been made to classify these cysts from 1887 to WHO 2017 head and neck tumors. Initially classified under developmental odontogenic cyst of jaw by WHO in 1971 and 1992, OKC has then been reclassified and renamed as KeratocysticOdontogenic Tumor (KCOT) in the WHO classifications of head and neck tumors in 2005 due to its aggressive behavior, high recurrence rates and specific histopathological feature. But recently WHO 2017 classification of head and neck tumors reclassified KCOT as a cyst. Despite of so many classification and nomenclature, unfortunately the controversy still exists. KCOT has been rarely reported to transform into a more aggressive lesion like ameloblastoma. We here present a case report of KCOT involving the body and ramus of the mandible having histopathological features suggestive of ameloblastomatic changes and mimicking dentigerous cyst.