ABSTRACT: Oral melanoma (OM) is an extremely rare and aggressive malignancy. A 67-year-old patient presented with complains of a slightly symptomatic spot in the mouth since the past 2 years. Extraoral examination revealed left cervical lymphadenopathy, and intraoral examination a blue-black multinodular sessile mass, with irregular margins, involving the attached gingiva of teeth 27 and 28, extending to vestibular sulcus and hard palate, measuring approximately 3.5 cm. The lesion presented focal areas of ulceration. Panoramic radiograph did not show bone involvement. The main diagnostic hypothesis was oral melanoma. Microscopic findings of the incisional biopsy revealed a proliferation of densely pigmented pleomorphic cells, invading the subepithelial connective tissue in sheets or nests showing an organoid pattern. Immunopositivity for S-100, Melan-A and HMB-45 confirmed the diagnosis of melanoma. The patient was referred to an oncology hospital in which multiple metastases were detected, and the patient was subjected to palliative care. Herein we report an OM in advanced clinical stage, and discuss the clinical, morphological and immunohistochemical diagnostic criteria with emphasis on the importance of early diagnosis.

RESUMEN: El melanoma oral (MO) es una malignidad extremadamente rara y agresiva. Un paciente de 67 años acudió a consulta con la queja de una mancha intraoral ligeramente sintomática, presente desde hace dos años. Al examen clínico extraoral, se encontró adenopatía cervical del lado izquierdo, y al examen intraoral, se observó una masa sésil multinodular de color negro azulado, focalmente ulcerada, con bordes irregulares, afectando la encía de los dientes 27 y 28, extendiéndose hasta el surco vestibular y el paladar duro, midiendo aproximadamente 3,5 cm. La radiografía panorámica no mostró involucramiento óseo. La principal hipótesis diagnóstica fue MO. Los hallazgos microscópicos de la biopsia incisional revelaron una proliferación de células pleomórficas densamente pigmentadas, invadiendo difusamente el tejido conectivo en forma de sábanas o nidos con patrón organoide. La positividad inmunohistoquímica para S-100, Melan-A y HMB-45 confirmó el diagnóstico de melanoma. El paciente fue referido a un hospital oncológico, en el cual se le detectaron múltiples metástasis y fue sometido a cuidados paliativos. Este es el reporte de un caso de MO diagnosticado en estado avanzado, en el que se discuten los criterios clínicos, morfológicos e inmunohistoquímicos para su diagnóstico, haciendo énfasis en la importancia del diagnóstico temprano.

OBJECTIVES: This study evaluated the resistance to antimicrobials of aerobes and facultative anaerobes isolated from patients wearing complete dentures, patients with gingivitis and periodontitis, and periodontally health subjects. MATERIAL AND METHODS: Three hundred and four isolates were tested. The minimal inhibitory concentrations of the drugs were evaluated through the agar dilution method using Mueller-Hinton agar. RESULTS: The most active antimicrobial drugs were the carbapenems (meropenem and imipenem), and resistance to these drugs was restrict to 1.6-2.3% of the isolates, as well as ciprofloxacin and rifampin. Microbial resistance to ampicillin, amoxicillin/clavulanic acid, cefoxitin, cephalothin, amikacin, chloramphenicol and nalidixic acid was particularly high. In most cases, the resistance to β-lactams was mediated by the production of hydrolytic enzymes, especially in gram-negative enteric rods, while enterococci did not evidence production of these enzymes. The association amoxicillin/clavulanic acid was not effective in 28.3% of the tested isolates. CONCLUSIONS: The results of this investigation confirmed that the oral cavity of patients with periodontitis and gingivitis, and particularly edentulous patients wearing complete dentures could harbor microorganisms with several antimicrobial resistance markers, and these microorganisms are frequently implicated in multiresistant, systemic, oral or nosocomial infections.