Journal of Dental Medicine

Background and Aims: Cathepsin-D is a well-known protease that promotes invasion in tumoral lesions. Considering the cystic neoplasm nature of odontogenic keratocyst (OKC), the aim of this study was to compare the expression of cathepsin-D in this lesion with the unicystic ameloblastoma (UA) and orthokeratinized odontogenic cyst (OOC) for better understanding of its behavior.
Materials and Methods: In this descriptive-analytical study, we used paraffin blocks available in the archives of oral and maxillofacial pathology department of dental school (8 unicystic ameloblastoma (UA), 8 odontogenic keratocyst (OKC) and 8 orthokeratinized odontogenic cysts (OOC)) which they were stained immunohistochemically with cathepsin-D. Then, the samples were observed simultaneously by two oral pathologists for detection the intensity and pattern of epithelial and stromal cells staining. Data were analyzed by SPSS20 and Kruskal-Wallis, Mann-Whitney and Chi-square test (P<0.05).
Results: The staining intensity of the epithelial cells of UA group was significantly more than OOC and OKC (P=0.02). The staining intensity of the stromal cells of UA was more than the other two groups, although this difference was not statistically significant (P=0.32). The pattern of cell staining in epithelium and stroma did not show any significant difference between the three groups in this study (P=0.15, 0.22).
Conclusion: The results of this study regarding the intensity expression of cathepsin-D in these three odontogenic lesions could be considered as a probable evidence for the new odontogenic lesions classification (WHO2017) in terms of reintroducing OKC as an odontogenic cyst. If this idea is rejected, it seems that cathepsin-D expression is not associated with the invasive behavior of this cyst, and further investigation of other markers in the epithelium and stroma simultaneously is suggested for a better understanding of its biological nature.

Introduction: Odontogenic keratocyst (OKC) is an odontogenic lesion with aggressive biological behavior, which occurs mainly in the posterior region of the mandible. Late diagnosis and treatment of this lesion is a significant diagnostic challenge.
Case report: The patient was a 12-year-old boy with complaints of progressive and painful swelling in the mandible for the past two months. The lesion ranged from the right first molar to the left first molar of the mandible. Panoramic radiography revealed a large multilocular radiolucent lesion with well-defined borders, which had caused bone loss and displacement of adjacent teeth. Considering the extension of the lesion in the midline region, the young age of the child along with other clinical and radiologic findings, the diagnosis of OKC was suggested which was ultimately confirmed by histopathologic examination.
Conclusion: The extensive spread of the lesion in an unusual site of OKC occurrence, its growth pattern, and the simultaneity of its occurrence with vitiligo in this case highlight the importance of reporting this case.