Estudo da frequência da mutação BRAF p. V600E em nevos melanocíticos e melanomas mucosos orais / Study of BRAF p. V600E mutation frequency in oral melanocytic nevi and oral mucosal melanomas

Nevos melanocíticos são neoplasias benignas derivadas de melanócitos. O nevo melanocítico adquirido comum cutâneo é frequente na pele humana e apresenta maior incidência na terceira década de vida. E, embora uma taxa pequena de transformação maligna tenha sido estimada, considera-se que os nevos adquiridos sejam precursores de uma parcela dos melanomas cutâneos. A mutação somática BRAF p.V600E, que ativa a via MAPK/ERK e proliferação celular, está implicada na formação dos nevos adquiridos comuns de pele e de um grupo de melanomas cutâneos, de sítios não cronicamente expostos ao sol. A partir da caracterização molecular do melanoma seu tratamento foi aprimorado pelo uso de inibidores de Braf e Mek. O nevo melanocítico adquirido mucoso oral (NMO) e o melanoma mucoso oral (MMO) são lesões raras e de patogênese incerta. Há escassa literatura sobre aspectos moleculares do NMO e um número ligeiramente maior de estudos sobre os MMOs, em sua maioria em séries que englobam uma mistura de diferentes tipos de melanomas mucosos de diversos sítios. No presente estudo, investigou-se a mutação BRAF p.V600E em um grupo de 14 NMOs intramucosos e 7 MMOs primários, excluídas amostras de lábio, por meio de reação em cadeia da polimerase alelo-específico (PCR-AE). Realizou-se também uma revisão narrativa de literatura para calcular a frequência da mutação BRAF p.V600E em NMOs e MMOs. Foram incluídos artigos originais em língua inglesa que exibissem o sítio primário da lesão e status mutacional, seja por amostra ou sua frequência. Informações sobre a idade dos pacientes, país de origem e tipo de tumor, se primário, recorrente ou metastático, e técnica de análise do DNA utilizada também foram coletadas. Cinco das quatorze amostras de NMOs (35,7%) avaliadas no presente trabalho foram positivas para BRAF p.V600E, enquanto três das sete amostras de MMOs (42,8%) exibiram a mutação. Na revisão narrativa de literatura, em conjunto com nossos resultados, 19 NMOs foram avaliados e 8 NMOs apresentaram a mutação BRAF p.V600E, correspondendo a uma frequência de 42,1%. Dos 374 MMOs avaliados, 24 MMOs exibiram a mutação BRAF p.V600E, totalizando a frequência de 6,4%. Em conclusão, amostras de NMOs e MMOs foram analisadas quanto à presença da alteração genética oncogênica BRAF p.V600E. E junto à revisão da literatura pode- se calcular a frequência da mutação em NMOs e MMOs, contribuindo para uma melhor caracterização molecular dessas lesões.

Melanocytic nevi are benign neoplasms derived from melanocytes. Common cutaneous acquired melanocytic nevus is frequently in human skin and it has a higher incidence in the third decade of life. Although a low rate of malignant transformation is estimated, a portion of cutaneous melanoma is preceded by a melanocytic acquired nevus. BRAF p.V600E somatic mutation activates the MAPK/ERK pathway and cell proliferation. It is implicated in the cutaneous melanocytic acquired common nevus pathogenesis and cutaneous melanoma that arise in sites not chronically sun-exposed. After melanoma molecular description, its therapeutic was improved by Braf and Mek inhibitors. Oral mucosal acquired melanocytic nevus (NMO) and oral mucosal melanoma (MMO) are rare lesions with uncertain pathogenesis. There is scanty literature about NMOs molecular features and few studies on MMOs. Most articles are series that evaluate mucosal melanomas from several sites collectively. In the present study, BRAF p.V600E mutation was assessed in 14 intramucosal NMOs and 7 primary MMOs, excluding lip samples, by allele specific quantitative polymerase chain reaction (AS-qPCR). A narrative literature review had been performed to calculate BRAF p.V600E frequency in NMOs and MMOs. Original articles in English language were included, since it was possible to identify the primary sample site and mutational status, by sample or its frequency. Data about patient age, country, type of tumor (primary, recurrent or metastatic) and sequence technique used also were collected. Five in fourteen NMOs samples (35.7%) analyzed in the present study were BRAF p.V600E positive and three in seven MMOs samples (42.8%) showed the mutation. In the narrative literature review, added to our results, 19 NMOs were evaluated and 8 NMOs presented BRAF p.V600E mutation, corresponding to a frequency of 42.1%. Between 374 MMOs evaluated, 24 MMOs showed the mutation totalizing the frequency of 6.4%. In conclusion, BRAF p.V600E oncogenic mutation was assessed in NMOs and MMOs samples. Additionally, in combination with the literature review, it calculated the mutation frequency in NMOs and MMOs, improving the molecular characterization of those lesions.

Late Diagnosis of Oral Melanoma / Diagnóstico Tardío de Melanoma Oral

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.

Radiation therapy as an adjuvant therapy for the treatment of oral melanoma in a dog / A utilização da radioterapia como terapia adjuvante no tratamento do melanoma oral em um cão

Background: Canine oral melanoma is highly aggressive, with an infi ltrative and metastatic behavior. The staging scheme for dogs with oral melanoma is primarily based on size, with stage I = 2 cm diameter tumor, stage II = 2 cm to 4 cm diameter tumor, stage III = 4 cm or greater tumor and/or lymph node metastasis and stage IV = distant metastasis. Surgery and radiation therapy are commonly used for local treatment of oral melanoma. Surgery must be aggressive and wide excision, such as partial mandibulectomy or maxillectomy, can be declined by owners. Median survival times for dogs with oral melanoma treated with surgery and chemotherapy is approximately seventeen, fi ve and three months with stage I, II and III disease, respectively. Radiation therapy plays a role in the local treatment of canine melanoma when the tumor is not surgically resectable, the tumor has been removed with incomplete margins and/or the melanoma has metastasized to local lymph nodes without further distant metastasis.Case: A dog with stage III oral melanoma was treated with radiation therapy and chemotherapy. The protocol consisted of three 8 gy radiation fractions (days 0, 7 and 21) delivered by an orthovoltage unit. Energy of 120 kV, 15 mA e 2 mm aluminum fi lter were used. Collimator size was 6 x 8 cm and source to skin distance was 30 cm. Dose rate was 187 cgy/ minute delivered at 1 cm tis

Background: Canine oral melanoma is highly aggressive, with an infi ltrative and metastatic behavior. The staging scheme for dogs with oral melanoma is primarily based on size, with stage I = 2 cm diameter tumor, stage II = 2 cm to 4 cm diameter tumor, stage III = 4 cm or greater tumor and/or lymph node metastasis and stage IV = distant metastasis. Surgery and radiation therapy are commonly used for local treatment of oral melanoma. Surgery must be aggressive and wide excision, such as partial mandibulectomy or maxillectomy, can be declined by owners. Median survival times for dogs with oral melanoma treated with surgery and chemotherapy is approximately seventeen, fi ve and three months with stage I, II and III disease, respectively. Radiation therapy plays a role in the local treatment of canine melanoma when the tumor is not surgically resectable, the tumor has been removed with incomplete margins and/or the melanoma has metastasized to local lymph nodes without further distant metastasis.Case: A dog with stage III oral melanoma was treated with radiation therapy and chemotherapy. The protocol consisted of three 8 gy radiation fractions (days 0, 7 and 21) delivered by an orthovoltage unit. Energy of 120 kV, 15 mA e 2 mm aluminum fi lter were used. Collimator size was 6 x 8 cm and source to skin distance was 30 cm. Dose rate was 187 cgy/ minute delivered at 1 cm tis

A utilização da radioterapia como terapia adjuvante no tratamento do melanoma oral em um cão / Radiation Therapy as an Adjuvant Therapy for the Treatment of Oral Melanoma in a Dog

Background: Canine oral melanoma is highly aggressive, with an infi ltrative and metastatic behavior. The staging scheme for dogs with oral melanoma is primarily based on size, with stage I = < 2 cm diameter tumor, stage II = 2 cm to < 4 cm diameter tumor, stage III = 4 cm or greater tumor and/or lymph node metastasis and stage IV = distant metastasis. Surgery and radiation therapy are commonly used for local treatment of oral melanoma. Surgery must be aggressive and wide excision, such as partial mandibulectomy or maxillectomy, can be declined by owners. Median survival times for dogs with oral melanoma treated with surgery and chemotherapy is approximately seventeen, five and three months with stage I, II and III disease, respectively. Radiation therapy plays a role in the local treatment of canine melanoma when the tumor is not surgically resectable, the tumor has been removed with incomplete margins and/or the melanoma has metastasized to local lymph nodes without further distant metastasis. Case: A dog with stage III oral melanoma was treated with radiation therapy and chemotherapy. The protocol consisted of three 8 gy radiation fractions (days 0, 7 and 21) delivered by an orthovoltage unit. Energy of 120 kV, 15 mA e 2 mm aluminum filter were used. Collimator size was 6 x 8 cm and source to skin distance was 30 cm. Dose rate was 187 cgy/minute delivered at 1 cm tissue depth, with the animal positioned in left recumbency. Treatment field included visible tumor plus a three cm margin. Lead sheets of 2 mm thickness were used to protect normal tissues around tumor. The dog was anesthetized with propofol (5 mg/kg EV) for correct position every radiation fraction. The chemotherapy consisted of four cycles of carboplatin (300 mg/m2 intravenously) administered every 21 days. The radiation therapy was well tolerated, and the only acute reaction observed in the irradiated field was epilation. The tumor had a partial remission of about 90% of the lesion, which was stable for six months. Discussion: The reported dog had a mandibular melanoma greater than 4 cm diameter with no evidence of regional or distant metastasis, and was diagnosed as having stage III disease. The animal was referred for radiation therapy because of non-acceptance of the owner to carry out the hemimandibulectomy, believing that the animal would have decreased quality of life to have a short survival even with surgery and chemotherapy. Radiation therapy was delivered with palliative intention to reduce tumor size and animal discomfort. With radiation therapy and chemotherapy, survival time was six months, exceeding the median survival for patients with stage III treated with wide surgical excision and chemotherapy (that would be three months), without showing side effects that diminish its quality of life. Systemic chemotherapy was used in the reported case with the purposes of acting as a radiopotentiation agent and delaying development of metastasis. Carboplatin has been used as radiopotentiation agent because it interferes with DNA synthesis. In the reported case, chemotherapy was well tolerated. Common radiation side effects include stomatitis, glossitis, skin epilation, erythema and desquamation. In the reported dog, treatment was very well tolerated, and only skin epilation was observed. Radiation therapy can be considered as an alternative option for oral melanoma when wide surgical resection is declined by owners.

Radiation therapy as an adjuvant therapy for the treatment of oral melanoma in a dog / A utilização da radioterapia como terapia adjuvante no tratamento do melanoma oral em um cão

Background: Canine oral melanoma is highly aggressive, with an infi ltrative and metastatic behavior. The staging scheme for dogs with oral melanoma is primarily based on size, with stage I = 2 cm diameter tumor, stage II = 2 cm to 4 cm diameter tumor, stage III = 4 cm or greater tumor and/or lymph node metastasis and stage IV = distant metastasis. Surgery and radiation therapy are commonly used for local treatment of oral melanoma. Surgery must be aggressive and wide excision, such as partial mandibulectomy or maxillectomy, can be declined by owners. Median survival times for dogs with oral melanoma treated with surgery and chemotherapy is approximately seventeen, fi ve and three months with stage I, II and III disease, respectively. Radiation therapy plays a role in the local treatment of canine melanoma when the tumor is not surgically resectable, the tumor has been removed with incomplete margins and/or the melanoma has metastasized to local lymph nodes without further distant metastasis.Case: A dog with stage III oral melanoma was treated with radiation therapy and chemotherapy. The protocol consisted of three 8 gy radiation fractions (days 0, 7 and 21) delivered by an orthovoltage unit. Energy of 120 kV, 15 mA e 2 mm aluminum fi lter were used. Collimator size was 6 x 8 cm and source to skin distance was 30 cm. Dose rate was 187 cgy/ minute delivered at 1 cm tis

Background: Canine oral melanoma is highly aggressive, with an infi ltrative and metastatic behavior. The staging scheme for dogs with oral melanoma is primarily based on size, with stage I = 2 cm diameter tumor, stage II = 2 cm to 4 cm diameter tumor, stage III = 4 cm or greater tumor and/or lymph node metastasis and stage IV = distant metastasis. Surgery and radiation therapy are commonly used for local treatment of oral melanoma. Surgery must be aggressive and wide excision, such as partial mandibulectomy or maxillectomy, can be declined by owners. Median survival times for dogs with oral melanoma treated with surgery and chemotherapy is approximately seventeen, fi ve and three months with stage I, II and III disease, respectively. Radiation therapy plays a role in the local treatment of canine melanoma when the tumor is not surgically resectable, the tumor has been removed with incomplete margins and/or the melanoma has metastasized to local lymph nodes without further distant metastasis.Case: A dog with stage III oral melanoma was treated with radiation therapy and chemotherapy. The protocol consisted of three 8 gy radiation fractions (days 0, 7 and 21) delivered by an orthovoltage unit. Energy of 120 kV, 15 mA e 2 mm aluminum fi lter were used. Collimator size was 6 x 8 cm and source to skin distance was 30 cm. Dose rate was 187 cgy/ minute delivered at 1 cm tis

Lesiones pigmentadas de la mucosa oral / Pigmented lesions of the oral mucosa

Existe una gran variedad de lesiones o condiciones que producen un cambio de coloración o discromía en la mucosa oral. Entre éstas se encuentran las pigmentaciones que pueden ser de origen exógeno o endógeno y lesiones tumorales. Los pigmentos endógenos incluyen la melanina, hemoglobina, hemosiderina y caroteno. En cambio, las pigmentaciones exógenas se pueden provocar por tatuajes, intoxicación por metales pesados y tinciones.

There are a variety of injuries or conditions that produce a color change or dyschromia in oral mucosa. These dyschromias include pigmentation, that may be of endogenous or exogenous origin and malignant tumor. Endogenous pigments include melanin, hemoglobin, hemosiderin, and carotene. Instead exogenous pigmentation can result from tattoos, heavy metals and stains.