Melanoma primario maligno variedad rabdoide. A Propósitode un caso / Malignant primary melanoma rhabdoid variety. about a case

Resumen El melanoma primariovariedad rabdoide es unapresentación pocofrecuente.Reconocido como un subtipo histopatológico distinto de melanoma maligno generalmente observado en tumores metastásicos o recurrentes.El diagnóstico definitivo requiere el estudio de inmunomarcación y la identificación de células neoplásicas con marcadores melanocíticos. Clínicamente se han reportado mayormente de tipo nodular y amelanótico.

Summary Rhabdoid melanoma has been recognized as a histopathological subtype of malignant melanoma. It generally presents as a recurrent tumor, so its presentation as a primary lesion is infrecuent.Definitive diagnosis requires the study of immunostaining and the identification of neoplastic cells with melanocytic markers. Clinically, mostly nodular and amelanotic types have been reported.

AMELANOTIC MELANOMA- RARE CASE REPORT

Amelanotic melanoma is an uncommon type of of melanoma which lacks melanin pigment (1). Of all the melanoma cases, approximately 2- 8% cases represents amelanotic melanoma. The exact prevalence of this malignancy is more due to misdiagnosis. Due to lack of clinical criteria and pigmentation, the condition often detected late (2). Amelanotic melanomas are commonly found on the face, which shows microscopically the characteristics of desmoplasia (desmoplastic melanoma), but other body parts can also be involved (4)

Melanoma del cuerpo ciliar en un adulto joven: reporte de caso / Ciliary body melanoma in a young adult: a case report

Resumen Reporte de un caso: Femenino de 29 años de edad sin comorbilidades, con baja visual progresiva en ojo derecho de 1 mes de evolución. A la exploración oftalmológica agudeza visual de ese ojo en 20/80, conjuntiva bulbar superior con vaso centinela, masa retroiridiana color naranja vascularizada que subluxa el cristalino hacia inferior. Por ultrabiomicroscopía se evidencia una masa en domo dependiente del cuerpo ciliar de 4.87x5.74mm con reflectividad interna media y regular. Se realiza primeramente BAAF reportando melanoma, después se hace enucleación con resultado histopatológico de melanoma amelanótico. Posterior, se realiza implante de prótesis cosmética y se encuentra en seguimiento por oncología sin presentar datos de actividad tumoral después de 4 años. Discusión: Los melanomas uveales son la causa más común de tumores malignos intraoculares primarios en adultos, localizados principalmente en coroides (90%), siendo extremadamente rara su aparición en el cuerpo ciliar (6%) e iris (4%). El abordaje de un tumor del cuerpo ciliar debe incluir una anamnesis y exploración física completa con estudios paraclínicos adecuados para poder discernir entre los diagnósticos diferenciales. El ultrasonido ocular es el estudio auxiliar más importante ya que brinda características típicas propias del tumor. El tratamiento continúa basado en el COMS con un pronóstico sombrío. Los factores de mal pronóstico son presencia de metástasis, tamaño del tumor, extensión extraocular y estirpe epitelioide. Limitaciones: No se contaban con todas las alternativas de tratamiento. Originalidad: Caso inusual en pacientes jóvenes y por su sitio.

Abstract: Case report: 29-year-old female with no comorbidities, with progressive vision loss in the right eye of 1 month's evolution. On ophthalmological examination, visual acuity was 20/80, superior bulbar conjunctiva with sentinel vessel, vascularised orange retroiridian mass generating a lens subluxation inferiorly. Ultrabiomicroscopy revealed a dome-shaped mass dependent on the ciliary body measuring 4.87x5.74mm with medium and regular internal reflectivity. A FNA was done and melanoma was reported, then enucleation was performed with histopathological findings of amelanotic melanoma. Subsequently, a cosmetic prosthesis was implanted and the patient has been followed up by oncology with no evidence of tumour activity after 4 years. Discussion: Uveal melanomas are the most common cause of primary intraocular malignant tumours in adults, mainly located in the choroid (90%), being extremely rare in the ciliary body (6%) and iris (4%). The approach to a ciliary body tumour should include a complete anamnesis and physical examination with appropriate paraclinical studies to be able to discern between differential diagnoses. Ocular ultrasound is the most important ancillary study as it provides typical features of the tumour. Treatment is still based on COMS and the prognosis remains poor. Poor prognostic factors are the presence of metastases, tumour size, extraocular extension and epithelioid lineage. Limitations: Not all treatment alternatives were available. Originality: Unusual case in young patients and because of its site.

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)

Primary malignant melanoma of vagina: a case report

Primary malignant melanoma of the vagina is a rare and aggressive disease with worse prognosis as compared with non-genital melanomas or other vaginal malignant neoplasms. Presented here is a case of 42 years female with 3 months history of amenorrhea and vaginal discharge. On vaginal examination, a firm growth of size approximately 7-8 cm was found attached to the left postero-lateral wall of vagina and extending up to the introitus. On biopsy and histopathological examination, it was diagnosed as a case of high-grade malignant melanoma of amelanotic type. Radiotherapy was started as a part of treatment after consultation with an oncologist, considering non-resectable nature of the mass. The patient received first 5 cycles of radiotherapy but succumbed to the disease during treatment.

Melanoma desmoplásico mixto / Mixed desmoplastic melanoma

El melanoma desmoplásico es una variedad infrecuente de melanoma que se distingue por su presentación clínico-patológica y su comportamiento biológico. El diagnóstico temprano es un desafío por su presentación clínica variable, con predominio del componente dérmico y la frecuente ausencia de pigmento. En la histología se lo divide en puro y mixto y esta clasificación tiene importantes implicancias pronósticas. El espesor de Breslow promedio al momento del diagnóstico es mayor que en otras variantes de melanoma, sin embargo, la tendencia a generar metástasis ganglionares es menor.

Desmoplastic melanoma is a rare presentation of melanoma with a different clinical behavior compared to other histological variants. Its diagnosis in early stages is a challenge due to its variable clinical presentation, with a predominant dermal component and the frequent absence of pigment. Its histology is divided into pure and mixed type, and this classification has important prognostic implications. The average Breslow thickness at diagnosis is higher than in other melanoma variants. However, the tendency to lymph node metastasis is low.

Intravascular and Extravascular Migratory, Metastatic Melanoma of the Great Saphenous Vein

Melanoma blood vessel metastases are very uncommon. Wereport this very rare case of metastatic melanoma along thewall of great saphenous vein (GSV), showing intra and extravascular metastasis. By far only a single case of intravascularmetastatic melanoma (IVMM) of GSV and thirty six cases ofextravascular migratory metastatic melanoma (EVMM) ofGSV have been reported. In our case melanoma cells wereseen both inside and outside of the wall of GSV, and in thedermis. A 60 years old male presented with multiple swellingsupper left thigh since one and a half year. Patient wasoperated. All swellings, along with, part of saphenous vein tillthe knee, and small part of skin were excised under GA.Microscopically, hematoxylin and eosin sections given fromvarious sites showed features of malignant melanoma. Tumorcells were seen in the dermis, and the lumen, as well asoutside the wall of saphenous vein, but not in the epidermis.Only very few melanocytic granules were seen in a singlearea of a section. On Immunohistochemistry –, MarkersHMB45, S100 and Vimentin are strong immunoreactive. CKPAN was focal immunoreactive.In our case the melanoma spread along the wall of the GSV.This pericytic angiotropism of melanoma cells, also showingsigns of intravasation, which suggests that melanomacells may migrate along the external surface of vessels, amechanism termed ‘EVMM and also by invading the bloodvessels ‘IVMM’.

Melanoma lentigo maligno amelanótico / Amelanotic lentigo maligna melanoma

RESUMEN El melanoma lentigo maligno es un subtipo de melanoma invasor, que se localiza en áreas fotodañadas de cara y cuello, manifestándose como una mácula no muy definida, de varios colores de la gama del marrón y negro. La variante amelanótica es infrecuente en cualquiera de los subtipos cutáneos de melanoma. Presentamos el caso de una mujer de 63 años, que presentó un melanoma lentigo maligno de subtipo amelanótico y de localización infrecuente, en miembro inferior.

SUMMARY Lentigomalignamelanoma is a subtype of invasive melanoma, located in photodamaged skin, particularly of the face and neck. It appears as an ill- defined macula, of heterogeneous color, ranging from brown to black. The amelanotic variant is infrequent in any of the cutaneous melanoma subtypes. We report the case of a 63-year-old woman with amelanoticlentigomaligna melanoma, located in her lower right limb.

Immunohistochemistry: sole tool in diagnosing a rare case of primary vaginal amelanotic melanoma

We report a rare case of vaginal amelanotic melanoma. Malignant melanomas are cutaneous and extracutaneous tumors that arise from embryological remnants of neural crest cells/melanocytes. Amelanotic melanomas at such rare locations can be misdiagnosed both clinically and radiologically. Therefore, histopathological examination and immunohistochemistry are mandatory for the diagnosis of these tumors. We diagnosed this case using histopathology and confirmed the diagnosis based on the presence of immunohistochemical markers human melanoma black 45 (HMB45) and S-100.

Six Cases of Amelanotic Melanoma: Focused on the Difficulty of Early Differential Diagnosis / 대한피부과학회지

Amelanotic melanoma comprises only 1.8~8.1% of malignant melanomas, and is difficult to diagnose clinically due to the lack of the diagnostic evidence of clinical pigmentation. To our knowledge, it is rarely reported, and only 10 cases have been reported in the Korean dermatological literature. It presents rather conflicting features such as a pink or red macule, papule, plaque, or nodule mimicking various benign and malignant conditions; therefore, it is difficult to diagnose. We performed a review of six patients with amelanotic melanoma focusing on differential diagnosis, particularly at the time of the initial visit. Clinical impressions included pyogenic granuloma, dermatofibrosarcoma protuberans, eccrine poroma, epidermal cyst, keloid, pilomatricoma, and squamous cell carcinoma in addition to malignant melanoma. The biopsy specimens were consistent with malignant melanoma with little or no melanin pigment on hematoxylin and eosin and Fontana-Masson stains. Four of the six patients were positive for S-100 and HMB-45, but two patients were positive for S-100 only. We report these cases to remind clinicians of the necessity of including malignant melanoma in the differential diagnosis process when patients show poor and unpredictable responses to treatment after a clinical diagnosis of other benign and malignant conditions.

Amelanotic Melanoma Mimicking Eccrine Poroma / 대한피부과학회지

No abstract available.

c-Kit immunoexpression patterns differ in melanotic and amelanotic canine oral melanomas / Análise qualitativa quanto à diferença da imunoexpressão do gene c-Kit em melanomas melânicos e amelânicos da cavidade oral em cães

Melanomas are the most common oral malignancy in dogs. Cell proliferation and connexin expression has been shown to differ in canine melanotic and amelanotic oral melanomas. This study aimed to analyze the c-Kit protein expression in melanotic and amelanotic melanomas from canine buccal cavity. A total of 34 canine buccal melanomas (19 melanotic and 15 amelanotic).were collected. The amelanotic melanomas presented faster evolution and higher incidence of metastasis than melanotic tumors. A significantly higher number of c-Kit positive cells were observed in amelanotic neoplasms. In addition, the intensity of c-Kit immunolabeling was predominantly stronger in amelanotic melanomas. These results confirm a potential role for c-Kit in canine oral melanomas with clear differences in expression patterns between the two histological types of tumor, melanotic and amelanotic. This study highlights the importance of a detailed study of c-Kit mutations in canine oral melanomas to better understand the molecular mechanisms implicated in the development of this disease...

Melanomas são as mais frequentes neoplasias malignas da cavidade bucal de cães. Sabe-se que a proliferação de células e expressão de conexina diferem em melanomas melanóticos e amelanóticos da cavidade bucal de cães. Este estudo analisou a expressão da proteína c-Kit em melanomas melanóticos e amelanóticos da cavidade bucal canina. Um total de 34 melanomas bucais caninos (19 melanóticos e 15 amelanóticos) foram coletados. Os melanomas amelanóticos apresentaram evolução mais rápida e maior incidência de metástase. Foi constatado um número significativamente maior de células positivas para c-Kit em neoplasias amelanóticas. Além disso, a intensidade de imunomarcação de c-Kit foi predominantemente mais forte em melanomas amelanóticos. Estes resultados confirmam um papel potencial para c-Kit em melanomas orais caninos, com diferenças claras em padrões de expressão entre os dois tipos histológicos de tumor, melanóticos e amelanóticos. Este trabalho destaca a importância de um estudo detalhado das mutações c-Kit em melanomas orais caninos para ser possível a melhor compreensão dos mecanismos moleculares envolvidos no desenvolvimento da doença...

A Case of Amelanotic Malignant Melanoma of the Maxillary Sinus Presented with Intraoral Extension

Melanoma of the sinonasal cavity has a high incidence of amelanotic presentation. Its diagnosis is difficult for clinicians and pathologists because of its hidden location and lack of pigmentation at the microscopic level. We reported a case of amelanotic melanoma of the maxillary sinus that showed aggressive extension to the oral cavity after extraction of the maxillary tooth. Histologically, the lesion resembled a plasmacytoid tumour. Diagnosis was made through the positive immunohistochemical staining for S100 and HMB-45.

Amelanotic Acral Melanoma Associated with KIT Mutation and Vitiligo

Amelanotic acral melanoma is rare and difficult to diagnose, both clinically and pathologically. KIT mutations are frequently found in acral melanomas and are considered a risk factor for poor prognosis. The presence of vitiligo in melanoma has been reported, and KIT is thought to be partly responsible for the dysfunction and loss of melanocytes observed in vitiligo. We report a case of amelanotic subungual melanoma with multiple metastases that was associated with KIT mutation and vitiligo. An 85-year-old man presented with a 3-year history of a tender erythematous ulcerated tumor on the left third fingertip and developed hypopigmented patches on the face and trunk. Histopathological examination of the ulcerative tumor showed aggregates of tumor cells that were pleomorphic epithelioid cells. Immunohistochemical staining of the tumor cells was positive for S100, HMB45, and c-Kit. Histopathological findings from the hypopigmented patch on the face were consistent with vitiligo. Mutation analysis showed a KIT mutation in exon 17 (Y823D). The patient had metastasis to the brain, liver, bone, and both lungs. The patient refused chemotherapy, and died 3 months after the first visit.

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.

An Ulcerative Amelanotic Melanoma on the Heel / 대한피부과학회지

No abstract available.

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.

Polypoid Amelanotic Melanoma on the Thigh / 대한피부과학회지

Amelanotic maliganat melanoma is a comparatively rare disease. It accounts for 1.8~8.1% of all malignant melanoma. It is sometime difficult to diagnose amelanotic malignant melanoma because there is no pigmentation, clinically. Polypoid melanoma is a variant of nodular melanoma, which in depth seldom reaches the reticular dermis. The main part of the tumor is located above the nearby epidermis, raised in the form resembling cauliflower. We report a rare case of amelanotic malignant melanoma with polypoid feature in a 78-year-old woman who presented a single bright red nodule on the left thigh.

Melanoma amelanótico en ciego / Cecal amelanotic melanoma

Paciente varón de 73 años que acude a emergencia con anemia severa (Hb 4.9 g/dL), refiriendo un mes con deposiciones oscuras, astenia y pérdida significativa de peso. La evaluación endoscópica alta no encontró lesiones potencialmente sangrantes. Posteriormente se constató la presencia de heces sanguinolentas rojizas tipo enterorragia y se realizó una colonoscopía, en la cual se encontraron dos lesiones elevadas en el ciego: una pedunculada (con sangrado activo rezumante) y otra sésil, ambas fueron extirpadas; el estudio de anatomía patológica demostró que correspondían a melanoma amelanótico de ciego. El examen físico no reveló lesiones neoplásicas dérmicas. El sangrado digestivo recurrente obligó a realizar una nueva colonoscopia que demostró una nueva lesión sangrante de ciego. Fue intervenido quirúrgicamente con una cecostomía y extirpación de la lesión cecal. La tomografía demostró metástasis en mediastino y en la cirugía se encontraron implantes metastásicos en hígado e intestino delgado. El paciente continuó tratamiento en oncología médica. Nosotros reportamos el presente caso, por ser la hemorragia digestiva una forma inusual de presentación clínica del melanoma maligno metastásico.

A 73 year old male patient who presented to emergency with severe anemia (Hb 4.9 g / dL), referring to a month with dark stools, fatigue and significant weight loss. The high endoscopic evaluation found no potentially bleeding lesions. Subsequently, we confirmed the presence of red blood in stools, like enterorrhagia and underwent a colonoscopy, in which two elevated lesions were found in the cecum: a pedunculated (with active bleeding, oozing) and other sessile; both were removed. the pathology showed that corresponded to amelanotic melanoma in cecal region. Physical examination revealed no malignant skin lesions. Recurrent gastrointestinal bleeding forced to make another colonoscopy that showed new bleeding lesion of the cecum. He was operated with a cecostomy and cecal excision of the lesion.. The tomography scan showed metastases in mediastinum and surgical implants were found in liver metastases and small intestine. The patient continued treatment in medical oncology. We report this case, because gastrointestinal bleeding is an unusual clinical presentation of malignant melanoma.

Nodular amelanotic melanoma.

We report a case of 65-year-old male patient who presented with multiple erythematous papules coalescing to form a nodular mass over posterior aspect of right thigh of six months duration. His general and systemic examinations were within normal range except for right inguinal lymphadenopathy. Biopsy from the lesion was done, which showed diffuse infiltrate of nests of atypical melanocytes extending upto reticular dermis. Malignant cells were positive for S100 and human melanin black 45(HMB 45). Hence, a diagnosis of amelanotic melanoma (AM) - Clarke level IV and TNM stage III was reached. MRI of involved leg showed fungating soft tissue mass in the posterolateral aspect of right thigh and metastatic right inguinal adenopathy. Fine needle aspiration cytology (FNAC) from the right inguinal nodes confirmed metastasis of melanoma. The patient was referred to oncosurgery department for further management.