RESUMO
Melanomas are malignant neoplasms originating from melanocytes. They occur in most animal species, but the dog is considered the best animal model for the disease. Melanomas in dogs are most frequently found in the buccal cavity, but the skin, eyes, and digits are other common locations for these neoplasms. The aim of this review is to report etiological, epidemiological, pathological, and molecular aspects of melanomas in dogs. Furthermore, the particular biological behaviors of these tumors in the different body locations are shown. Insights into the therapeutic approaches are described. Surgery, chemotherapy, radiotherapy, immunotherapy, and the outcomes after these treatments are presented. New therapeutic perspectives are also depicted. All efforts are geared toward better characterization and control of malignant melanomas in dogs, for the benefit of these companion animals, and also in an attempt to benefit the treatment of human melanomas.
RESUMO
A small proportion of cases diagnosed as oral lichen planus (OLP) and oral lichenoid lesions (OLL) can undergo malignant transformation. Some authors, however, stand that only dysplastic lichenoid lesions, not true OLP, have the potential to progress to oral squamous cell carcinoma (OSCC). The histologic diagnosis is a subjective resource and is not always accurate in differentiating OLP from OLL. Thus, this study attempted to evaluate the malignant potential of lesions diagnosed as OLP and as OLL without dysplasia. The Streptavidin-biotin method of immunohistochemistry was used for the staining with p53 and Ki67 in 22 cases of OLP and 27 cases diagnosed as OLL. Ki67 immunoexpression was not statistically different between OLP and OLL (p = 0.353), but, p53 staining showed a significant contrast (p = 0.036). A higher average of staining was detected in the group of OLP. The study showed that apparently a diagnosis of OLP or OLL makes no difference for the patient regarding malignant transformation, although in OLP p53 showed a higher index of expression, probably related to the intensity of inflammatory infiltrate.
Assuntos
Antígeno Ki-67/metabolismo , Erupções Liquenoides/patologia , Neoplasias Bucais/patologia , Lesões Pré-Cancerosas/patologia , Proteína Supressora de Tumor p53/metabolismo , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Progressão da Doença , Humanos , Técnicas Imunoenzimáticas , Líquen Plano Bucal/metabolismo , Líquen Plano Bucal/patologia , Erupções Liquenoides/metabolismo , Neoplasias Bucais/metabolismo , Lesões Pré-Cancerosas/metabolismoRESUMO
Three young, female dogs were operated for compound odontoma. All tumors were considered stage III with treatment consisting of partial mandibulectomy or maxillectomy. Microscopic examination of the resected tissue confirmed the diagnosis. Relatively aggressive, resective surgery resulted in prolonged tumor-free intervals.
Assuntos
Doenças do Cão/cirurgia , Neoplasias Mandibulares/veterinária , Neoplasias Maxilares/veterinária , Odontoma/veterinária , Animais , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/patologia , Cães , Feminino , Neoplasias Mandibulares/cirurgia , Neoplasias Maxilares/cirurgia , Estadiamento de Neoplasias , Odontoma/cirurgia , Radiografia , Cirurgia VeterináriaRESUMO
A modified hemimandibulectomy was performed for treatment of oral neoplasms in 21 dogs. Intra- and postoperative evaluations included assessment of procedure difficulty, complications, mastication, cosmesis, and the time interval between surgery and recurrence of the neoplasm or clinical evidence of metastasis. Malignant melanoma was the most common neoplasm treated using this technique. The modified hemimandibulectomy was uncomplicated with minimal intraoperative hemorrhage. Three dogs had difficult mastication at 24-hours following surgery, while 5 dogs had partial wound dehiscence. Wound infection was diagnosed in 1 dog. All owners considered the postoperative outcome to provide acceptable cosmesis. Local neoplasm recurrence was documented in 5 dogs and distant (pulmonary) metastasis was diagnosed in 5 different dogs following surgery. The technical modification described in this study seemed to provide for improved mastication during the acute postoperative period compared with other hemimandibulectomy techniques performed by the authors.
Assuntos
Doenças do Cão/cirurgia , Neoplasias Mandibulares/veterinária , Animais , Carcinoma de Células Escamosas/secundário , Carcinoma de Células Escamosas/cirurgia , Carcinoma de Células Escamosas/veterinária , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/patologia , Cães , Feminino , Fibrossarcoma/secundário , Fibrossarcoma/cirurgia , Fibrossarcoma/veterinária , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/veterinária , Metástase Linfática/patologia , Masculino , Neoplasias Mandibulares/patologia , Neoplasias Mandibulares/cirurgia , Melanoma/secundário , Melanoma/cirurgia , Melanoma/veterinária , Recidiva Local de Neoplasia/veterinária , Estadiamento de Neoplasias/veterinária , Complicações Pós-Operatórias/veterinária , Radiografia , Cirurgia Bucal/métodosRESUMO
In order to establish the diagnosis and prognosis of tumors of the oral cavity, a comparative study was carried out in 130 dogs considering age, sex, breed, clinical aspects, exfoliative cytology as well as histopathology. Exfoliative cytology revealed: 100 percent negative for benign non-odontogenic tumors, 97.91 percent negative benign odontogenic tumors and 77.92 percent positive for malignant tumors.Histopathology showed: 59.23 percent malignant tumors (33.08 percent malignant melanoma, 9.23 percent squamous cell carcinoma, 5.38 percent osteosarcoma, 2.31 percent fibrosarcoma, 2.31 percent angiosarcoma, 1.54 percent malignant mesenchymal tumors, 1.54 percent malignant fibrohistiocytoma, 1.54 percent lymphoma, 0.77 percent leyomyosarcoma, 0.77 percent epithelioid sarcoma and 0.77 percent angiofibrosarcoma); 36.92 percent benign odontogenic tumors (25.38 percent peripheral odontogenic fibroma, 10.0 percent ossifyng fibroma and 1.54 percent odontoma) in addition to 3.85 percent benign non-odontogenic tumors (1.54 percent fibroma, 0.77 percent plasmocytoma, 0.77 percent pilomatrixoma and 0.77 percent giant tumor cells). These results permit us to conclude that exfoliative cytology was an efficient, safe, quick and noninvasive method and coul be used for early evaluation of oral cancer.