RESUMO
Low-grade myofibroblastic sarcoma is a malignant tumour from myofibroblasts, which has only recently become clearly defined. It represents a rare entity developing in the soft tissues of the head and neck. About 20 cases have been reported in the oral cavity, especially in the tongue and bone, while gingiva as the primary site has been described only once to date. Diagnostic methods include histology and immunohistochemistry. The present report concerns a case of a 37-year-old man who presented with a persistent gingival ulcerated swelling that was interpreted for a long time as a gingival epulis. A low-grade myofibrosarcoma was diagnosed and the patient underwent a segmental osteotomy of the mandibular symphisys for complete excision. There was no sign of recurrence or metastatic disease during the 18-month postoperative period.
Assuntos
Neoplasias Gengivais/diagnóstico , Neoplasias Mandibulares/diagnóstico , Neoplasias de Tecido Muscular/diagnóstico , Osteossarcoma/diagnóstico , Adulto , Biomarcadores Tumorais/análise , Biópsia , Gengiva/patologia , Gengiva/cirurgia , Neoplasias Gengivais/patologia , Neoplasias Gengivais/cirurgia , Humanos , Masculino , Neoplasias Mandibulares/patologia , Neoplasias Mandibulares/cirurgia , Neoplasias de Tecido Muscular/patologia , Neoplasias de Tecido Muscular/cirurgia , Osteossarcoma/patologia , Osteossarcoma/cirurgia , Osteotomia , Tomografia por Emissão de Pósitrons , Radiografia Panorâmica , Tomografia Computadorizada por Raios XRESUMO
p53 over-expression has been proposed as a reliable marker associated to oral carcinogenesis, although only about 50% of oral carcinomas (OSCC) are associated with p53 over-expression and even p53-negative lesions can progress to OSCC. The aim of the study was to determine whether the combination of p53 over-expression and p53 low-expression associated with Ki67 over-expression (high Ki67/p53 ratio) could lead to a more sensitive parameter. Immunohistochemical expression of Ki67 and p53 was measured in 54 specimens from OSCC; 27 specimens from moderate/severe epithelial dysplasia; 32 specimens from oral leukoplakias without epithelial dysplasia, and 13 specimens with normal epithelium. p53 over-expression was found in 31 (53%) samples from OSCC, in 10 (37%) samples from severe dysplasias, and in 5 (15%) samples from non-dysplastic lesions, while the combination of high p53 values with high Ki67/p53 ratio was observed in 93% of OSCC, in 81% of dysplastic lesions, and in 50% of non-dysplastic lesions. This parameter may have a clinical implication to detect early lesions with an impairment of p53 pathway, and probably at risk of progress to OSCC.
