Análise dos parâmetros clínicos, imaginológicos, cirúrgicos, histológicos e taxas de recidiva de ameloblastoma tratados no serviço de cirurgia e traumatologia bucomaxilofacial do Hospital das Clínicas da UFMG: uma coorte retrospectiva

Abstract

Ameloblastoma is a benign odontogenic neoplasm originating from remnants of odontogenic epithelium which grows slowly but infiltrating the surrounding tissues. It has three clinical variants: conventional, unicystic and peripheral, according to which differ in their biological behavior and consequently in their response to the available therapeutic modalities. These modalities are classified as conservative (enucleation and surgical excision) and radical (marginal and segmental resection) ones. Conservative techniques are used for the treatment of unicystic ameloblastoma, due to its encapsulated aspect, and for the peripheral subtype. Radical techniques are advised for the management of conventional ameloblastoma. The available treatment protocols vary between surgeons and their use is influenced by clinicoradiographic aspects (location and size of the lesion, involvement of adjacent teeth, age, history of recurrences, surgeon preference), histological subtype and literary (lack of standardization of data relating to the issue). For this reason, the present study will retrospectively analyze cases of ameloblastoma treated uniformly by the same surgeon from 2002 to 2023. The sample was formed by 12 cases of unicystic and 24 cases of conventional ameloblastomas. These groups were analyzed separately. There was a female predilection, and the mean age of patients were 27,25 and 40,2 years respectively. Almost all lesions affected the posterior mandible in both groups. Radiographically, we observed a predominant unilocular pattern for unicystic ameloblastoma (91,7%) and a multilocular pattern for conventional ones (83%). Lesions measured, on average, 46,14mm and 41,06mm respectively. Root resorption, tooth displacement and cortical perforation were also observed. The mural histological subtype corresponded to 75% of the unicystic cases, while follicular pattern (79%) was predominant in conventional samples. Microscopic analysis of margins for tumour infiltration was performed in conventional ameloblastoma samples and revealed 4 positive margins (16%) and 20 margins free of disease (83%). Regarding the surgical therapy adopted, all unicystic cases (n=12, 100%) were treated conservatively (enucleation + peripheral ostectomy + cauterization with Carnoy's solution) and all cases of conventional ameloblastoma (n=24; 100%) underwent marginal/segmental resection. No additional approach was used in cases of conventional ameloblastoma that presented infiltrated margins. Recurrence occurred in 8,33% of both groups, corresponded to one mural and two follicular ameloblastomas whose margins were free of disease, which does not exclude the possibility of recurrence. The mean follow up period was 62 and 79 months, respectively. Our findings suggest that a conservative approach should be the first option for the treatment of unicystic ameloblastoma, even for those with mural proliferation. Conventional ameloblastomas, on the other hand, should be managed through a radical approach due to its infiltrative behavior.