Oral pigmented lesions: a retrospective analysis from Brazil / Lesiones pigmentadas orales: un análisis retrospectivo desde Brasil

Background: Pigmented lesions are uncommon in the oral mucosa, and studies investigating the incidence andtypes of these lesions are desired to improve the diagnostic knowledge of clinicians. The aim of this study was toanalyze the distribution of oral pigmented lesions in a Brazilian population.Material and Methods: A retrospective descriptive cross-sectional study was performed. Oral pigmented lesionswere retrieved from the files of two oral and maxillofacial pathology services from Brazil over a 45-year period(1974-2019). The clinical data and the diagnoses of each case were retrieved and included in a Microsoft Excel®database.Results: From 77.074 lesions diagnosed in this period, 761 (0.99%) represented pigmented lesions of the oralmucosa, including 351 (46.1%) melanocytic and 410 (53.9%) non-melanocytic lesions, with a higher incidence infemales (73.2%) between the fourth and seventh decades of life. Amalgam tattoo (53.6%) represented the most common lesion, followed by melanotic macule (18.3%) and racial pigmentation (10.8%). Other pigmented lesionsincluded nevus (9.9%), post-inflammatory pigmentation (3%), melanoma (2.1%), melanoacanthoma (1.4%), smoker'smelanosis (0.4%), drug-induced pigmentation (0.3%), and melanotic neuroectodermal tumor of infancy (0.1%). Thebuccal mucosa was the most commonly affected site (25.2%), followed by the alveolar ridge (14.5%), and gingiva(11.8%).Conclusions: The current findings were similar to previous studies with minor differences due methodology andcharacteristics of the services from where lesions were retrieved. The knowledge of these data may contribute to abetter understanding of oral pigmented lesions and assist clinicians to better recognize and manage them.(AU)

Calcifying Odontogenic Cyst Associated With Dentigerous Cyst in a 15-Year-Old Girl.

Calcifying odontogenic cyst (COC) is a rare odontogenic cyst with ameloblastic epithelial lining containing clusters of ghost cells. COCs have been described in association with several odontogenic tumors, more commonly odontomas and rarely with dentigerous cyst (DC). In this article, we describe a case of COC associated with DC in a 15-year-old girl, who presented with a swelling on the right middle third of the face, producing facial asymmetry. Panoramic radiography showed a well-circumscribed, corticated, and unilocular radiolucency at the level of the right maxillary sinus, involving 2 unerupted premolars. The lesion was enucleated and histologically revealed a COC associated with DC, which presented mucous metaplasia. Immunohistochemical reactions were performed to better illustrate this rare synchronous occurrence of COC and DC, showing positivity for CK5, CK14, CK19, and p63 in both lesions. CK18 was negative in COC, and Bcl-2 was negative in DC. Periodic acid Schiff highlighted the mucous cells in the DC lining.