Melanoma amelanótico diseminado / Disseminated amelanotic melanoma

El melanoma amelanótico es una de las neoplasias con mayor índice de mortalidad por su alta agresividad y baja probabilidad diagnóstica. Afecta a la población de todo el orbe, más frecuente en caucásicos, con predisposición genética y factores de riesgo como la exposición al sol. Presenta tasas de supervivencia menor a 10 por ciento a 5 años y de recurrencia elevadas; con evidencia de procesos metastásicos a distancia en órganos como cerebro, tejido celular subcutáneo, pulmón, peritoneo, hueso, lo que ensombrece el pronóstico. Se presenta el caso de una paciente de 21 años de edad que acude al hospital por presentar lesiones equimóticas, nódulos subcutáneos y cefalea hemicránea izquierda de dos meses de evolución. Se le realizó tomografías de tórax abdomen y resonancia magnética de cráneo y evidenciaron diseminación metastásica. Se realizó estudio histopatológico con inmunohistoquímica que informó melanoma amelanótico(AU)

Amelanotic melanoma is one of the neoplasms with the highest mortality rate because it is highly aggressive and the diagnostic probability is low. It affects the population of the entire globe, more frequent in Caucasians, with genetic predisposition and risk factors such as sun exposure. It presents survival rates of less than 10 percent at 5 years and high recurrence rates; with evidence of distant metastatic processes in organs such as brain, subcutaneous cellular tissue, lung, peritoneum, bone, which casts a shadow on the prognosis. We report the case of a 21-year-old patient who came to the hospital due to ecchymotic lesions, subcutaneous nodules and a two-month evolution of left hemicrania headache. She underwent chest and abdomen tomography and MRI of the skull. They showed metastatic spread. Histopathological study was performed with immunohistochemistry that reported amelanotic melanoma(AU)

Amelanotic acral melanoma misdiagnosed as verruca plantaris

Abstract: We report a case of amelanotic acral melanoma in a 42-year-old Chinese woman. Ten months previously the patient found a 2-cm asymmetric erythematous macular plaque on her left sole. The lesion was diagnosed as verruca plantaris by every physician the patient consulted. One month ago, an enlarged lymph node was detected in the left groin, which biopsy reported as metastatic melanoma. Dermoscopy suggested verruca plantaris, and positron emission tomography (PET) revealed increased glucose metabolism in the macular plaque. Finally, biopsy of the plaque revealed amelanotic melanoma. Misdiagnosis and diagnostic delay are usually associated with poorer patient outcomes. Awareness of atypical presentations of acral melanoma is thus important for decreasing misdiagnosis rates and improving patient outcomes.

Primary cutaneous amelanotic melanoma and gastrointestinal stromal tumor in synchronous evolution

Abstract: Gastrointestinal stromal tumor is rare digestive tract mesenchymal tumor, most often in the wall of the stomach. It is a benign neoplasm, but it can become malignant if not treated. We report a case of gastrointestinal stromal tumor that was discovered after abdominal ultrasonography during staging of a patient with primary cutaneous amelanotic melanoma. Mutation in the tyrosine kinase receptor could explain the development of two types of tumors in the same patient.

Melanoma amelanótico acral en un paciente diabético / Acral amelanotic melanoma in a diabetic patient

Melanoma is one of the most aggressive and worse prognosis tumors. Early diagnosis is essential to offer therapeutic alternatives. Presentation may be variable. Within these the amelanotic melanoma form. We present the case of a patient treated at the ¨Hospital Regional de Talca¨, with an unclear diagnosis of melanoma at a first moment given the characteristics and location of the lesion, the history of trauma and the patient comorbidities, which after biopsy and immunohistochemical analysis, the diagnosis of amelanotic melanoma is possible.

Oral Mucosal Amelanotic Melanoma: A Rare Case Report.

Oral cancer is a major global health problem. It is ranked as the third most common cancer in India. More than 95% of oral cavity carcinomas are of squamous cell type. Melanoma is a major health problem and originates from the malignant transformation of melanocytes. Primary mucosal melanomas of the head and neck occur less frequently than their cutaneous counterparts. Among those, oral mucosal melanoma is extremely infrequent with an incidence of 0.5% of oral neoplasms. Less than 2% of all melanomas lack pigmentation, in the oral mucosa, however, up to 75% of cases are amelanotic melanomas. Th ese are extremely rare variants and the most frequent sites in the oral cavity are the hard palate and the gingiva. Lesions that are suspected to be melanomas should be assessed both histologically and by immunohistochemistry, which are helpful in the diagnosis of amelanotic melanoma. Th ey have a poorer prognosis than the pigmented melanomas because of the delay in diagnosis and in the initiation of treatment. Th is presentation is a rare case report of oral mucosal amelanotic melanoma.

Melanoma amelanótico em cães: estudo retrospectivo de 35 casos (2004-2010) e caracterização imuno-histoquímica / Amelanotic melanoma in dogs: a retrospective study of 35 cases (2004-2010) and immunohistochemical characterization

Melanomas são tumores agressivos de melanócitos que ocorrem principalmente na cavidade oral, nas junções mucocutâneas e na pele de cães. Este tipo de neoplasma pode apresentar diversos graus de pigmentação melânica, incluindo total ausência (melanomas amelanóticos [MA]). Os arquivos de biópsia do SPV-UFRGS, que compreendem o período de 2004 a 2010, foram revisados e levantados os casos de neoplasias melanocíticas em cães. Realizou-se estudo retrospectivo de 35 casos de MA e caracterização pela imuno-histoquímica (IHQ). As principais raças acometidas foram o Poodle, Dachshund e Cocker Spaniel, mas o maior número de casos foi observado em cães sem raça definida (SRD). A idade média desses cães foi de 10,7 anos (variação de 5 a 18 anos) e não houve predileção por sexo. As principais localizações incluíram cavidade oral (57,1%) e dígitos (17,1%). Histologicamente, 40% dos MA foram classificados como epitelioides, 34,3% como mistos e 25,7% como fusiformes. Na avaliação IHQ, 86,6% dos casos foram positivos para a vimentina, 70% para a proteína S-100 e 56,6% para o melan-A. Os resultados obtidos neste trabalho possibilitam concluir que os cães com MA caracterizavam-se por serem velhos. A forma celular mais observada foi a epitelioide. Devido a pouca diferenciação desses tumores, ressalta-se a importância da realização do painel imuno-histoquímico, sobretudo da proteína S-100, que apresentou melhor marcação que o melan-A.

Melanomas are aggressive tumors of melanocytes. They are common in dogs and involve mainly the oral cavity, mucocutaneous junction, and skin. Furthermore, these tumors could be highly pigmented or lack pigment. The biopsies archives from SPV-UFRGS, 2004 to 2010, were retrieved and melanocytic neoplasms in dogs were revised. A retrospective study of 35 cases of amelanotic melanomas (AM) was performed, also immunohistochemistry (IHC) characterization was evaluated. The dogs more affected were mixed breed followed by Poodle, Dachshund and Cocker Spaniel. The average age of the dogs was 10.7 years (5-18 years in age) and there was no sex predilection. The locations of the neoplasms were the oral cavity (57.1%) and digits (17.1%). Histologically, 40% were classified as epithelioid, 34.3% mixed and 25.7% spindle. The positive immunostaining for vimentin, S-100 protein and melan-A were 86.6%, 70%, and 56.6% respectively. These results indicated the most affected dogs with AM were elderly. Epiteliod classification was the most observed histologically. It is important to perform IHC, due to lacking of differentiation of AM, mainly, anti S-100 protein that showed to be the best option of positive marker, even better to Melan-A.

Oral Amelanotic Melanoma

Malignant melanomas of the mucosal regions of the head and neck are extremely rare neoplasms accounting for less than 1of all melanomas. Approximately half of all head and neck melanomas occur in the oral cavity. Less than 2of all melanomas lack pigmentation; in the oral mucosa however; up to 75of cases are amelanotic. No etiologic factors or risk factors have been recognized for oral melanomas. Some authors have suggested that oral habits and selfmedication may be of etiological significance. Oral melanoma is rare but it is relatively frequent in countries like Japan; Uganda; and India. It is rarely identified under the age of 20 years. In Australia where cutaneous melanomas are relatively common primary melanoma of the oral mucosa is rare. The surface architecture of oral melanomas ranges from macular to ulcerated and nodular. The lesion is said to be asymptomatic in the early stages but may become ulcerated and painful in advanced lesions. The diagnosis of amelanotic melanoma is more difficult than that of pigmented lesions. The neoplasm consists of spindle-shaped cells with many mitotic figures and no cytoplasmic melanin pigmentation. Immunohistochemistry using S-100; HMB-45; Melan-A and MART-1 will help in establishing the correct diagnosis. Radical surgery with ample margins and adjuvant chemotherapy are appropriate management protocol for malignant melanoma. Oral melanoma is associated with poor prognosis but its amelanotic variant has even worse prognosis because it exhibits a more aggressive biology and because of difficulty in diagnosis which leads to delayed treatment

Melanoma amelanótico del pezón en un varón: presentación de un caso y revisión de la literatura / Amelanótico melanoma of the nipple in a man: presentation of a case and revision of literature

Se presenta un paciente de sexo masculino con un melanoma amelanótico ubicaco en pezón izquierdo, de 3 meses de evolución. Se realiza escisión amplia y la histopatología concreta el diagnóstico sospechado. Se enfatiza la literatura sobre melanoma de areola y pezón, llamando la atención la proporción importante del sexo masculino. Los diagnósticos diferenciales involucran distintas entidades patológicas, remarcándose aquellos con carcinoma basocelular y la enfermedad de Paget.

Metastatic amelanotic melanoma.

We report a 60 year-old-man who presented with generalized abdominal colicky pain. He had a history of left great toe dysarticulation done for amelanotic melanoma one year ago. Investigations were suggestive of metastases of melanoma to the small intestine. Exploratory laparotomy with segmental ileal resection and anastomosis was performed. Histological examination showed features of amelanotic melanoma characterized by absence of melanin pigment.

Melanoma amelanótico anorretal: relato de caso / Anorectal amelanotic melanoma: case report

Os melanomas anorretais representam entidade de ocorrência pouco frequente, com evoluçäo agressiva e conduta controversa. A cirurgia näo conseque curar a grande maioria dos casos, sendo que eles também näo respondem a radioterapia e quimioterapia. Os autores apresentam um caso de melanoma amelanótico de reto baixo, que se apresentou com hematoquezia persistente, tendo sido tratado pela amputaçäo abdominoperineal do reto

Melanoma maligno eczematoide / Eczematoid malignant melanoma

Objetivo: comunicar una forma rara de melanoma maligno amelanótico, denominada eczematoide o tipo placa inflamatoria. Caso clínico: paciente de sexo femenino y 74 años de edad, que presenta una placa eczematoide en pierna, con diagnóstico histopatológico de melanoma extensivo superficial, nivel Clark IV e índice de Breslow 1,7 mm. Conclusión: recordar la existencia de melanomas "falsos negativos" o "evasores de campaña", que no cumplen con el ABCD clásico de los melanomas

Melanoma maligno: seguimiento y factores pronósticos en 109 pacientes / Malignant melanoma: follow-up and prognostic factors in 109 patients

Se presentan los hallazgos de un estudio retrospectivo, realizado con 109 pacientes portadores de melanoma maligno, diagnosticados en el Hospital Privado de Comunidad, de Mar del Plata, entre los años 1971-1991. Se constató una alta incidencia, del 0,04 por ciento de las consultas dermatológicas y del 0,001 por ciento de las consultas generales de dicho período de 20 años. Las edades estuvieron comprendidas entre los 25 y 93 años....

Estudo clínico, histopatológico e imunoistoquímico do melanoma amelanótico / Clinical, histopathological and immunohistochemical study of amelanotic melanoma

O autor realizou um estudo clínico, histopatológico e imunoistoquímico em 18 casos de melanoma amelanótico. Considera que esta variedade do tumor é pouco frequente, concordando com os achados da literatura. A escassez ou ausência de pigmento nos melanócitos anormais justifica a formulação de várias hipóteses clínicas, e tornam o diagnóstico histopatológico mais complexo. Apesar de um terço da amostra (7 casos) ter localização acral, não foi expressa opinião sobre esta topografia eletiva de Melanoma amelanótico. A pesquisa imunoistoquímica da proteína S100, enolase neurônio específica e do HMB45 foi positiva em 15 das 16 lesões examinadas. O único caso de negatividade aos 3 atributos antigênicos citoplasmáticos foi interpretado como decorrente de problema técnico de fixação e inclusão. A proteína S100, enolase neurônio específica e o HMB45 foram confirmados somente aos melanócitos neoplásicos. Isto lhe confere alto grau de especificidade e confiabilidade para o diagnóstico final imunoistoquímico do melanoma amelanótico.