Peripheral Calcifying Cystic Odontogenic Tumor: Report of a Case and Evidence Against its Neoplastic Classification

Problem Statement: The most recent World Health Organization (WHO) classification of odontogenic tumors published in Pathology and Genetics. Head and Neck Tumors in 2005 classifies the ghost cell lesions as neoplasms because there is a solid, non-cystic variant. However, most ghost cell lesions are cystic and the WHO offered no scientific evidence for reclassifying the cystic lesions as neoplasms. Accordingly, the reclassification has remained controversial. The most common lesion that contains ghost cells is the calcifying cystic odontogenic tumor (CCOT) or calcifying odontogenic cyst (COC), which is characterized by ameloblastic epithelium and numerous ghost cells. Approximately 20 percent of these are extraosseous. Even though the WHO defines this lesion as a neoplasm, it shows little neoplastic potential and has a low recurrence rate of around 5% with conservative enucleation or local excisional treatment. Does this classification truly describe lesion behavior and does it lead to appropriate treatment?

Methods: Case Report: A 33-year-old female presented to our clinic with a chief complaint of painful swelling of the right maxillary vestibule first noticed two years prior to presentation. There had been no noted discharge. The right nasolabial fold was obliterated. Clinical and radiographic examinations revealed an extraosseous, well-demarcated radiolucent lesion measuring 20mm by 21.5mm with cortical compression and adjacent root resorption. There was no trigeminal second division paresthesia. With a provisional diagnosis of nasolabial cyst, the lesion was surgically removed. Histopathology demonstrated a cystic lesion with ameloblastoma-like epithelium and numerous intraluminal ghost cells. The specimen was diagnosed as a peripheral calcifying cystic odontogenic tumor.

Method of Data Analysis: The investigators reviewed the radiographic, clinical, and histopathological features and compared them with reported cases in the literature and the WHO classification for ghost cell containing lesions.

Results: Including the presented case, there have been 47 (23 female, 18 male, 6 uninformed) reported cases of peripheral calcifying cystic odontogenic tumors.  The mean age was 48.1 years.  Clinically, 39 cases presented on gingiva, 2 cases presented within maxillary vestibule, 0 cases reported in mandibular vestibule, and 6 cases with uninformed location.  Radiographically, 3 cases presented with calcification, 7 presented with adjacent bone or root resorption, 13 cases presented with no calcification or adjacent bone or root resorption, and 24 cases with uninformed radiographic appearance.  With regards to recurrence with enucleation and local excision there was 1 reported recurrence (2.1%), 14 with no reported recurrence (30%), and 32 with uninformed recurrences (68%).

Conclusion: Recently, the nomenclature for PCCOTs has been questioned. Furthermore, There is little historical evidence of this lesion’s neoplastic potential. Therefore, to aid with naming confusion and help prevent surgical overtreatment, these investigators suggest revising the WHO classification for PCCOTs.

References:

Wright J, et al. Odontogenic Tumors, WHO 2005: Where DO we Go from Here? Head and Neck Pathol. (2014) 8:373-382

Lima A, et al. Peripheral Calcifying Cystic Odontogenic Tumour of the maxillary ginigva. BMC Research Notes (2012), 5:455