Eruptive melanocytic nevi in a patient with amelanotic melanoma: a paraneoplastic phenomenon?

Eruptive melanocytic nevi (EMN) describes the sudden onset of cutaneous nevi over weeks or months. Such a clinical event is generally seen in young adult patients and may be related to several possible causes. We report here a case of EMN in an old male patient followed up for a thick amelanotic cutaneous melanoma. A few months after the eruption, multiple hepatic masses, diagnosed as melanoma metastasis, were detected. The presented case may suggest that EMN may be a paraneoplastic phenomenon of alert in patients being followed for melanoma or other malignancies.

Spontaneous subcapsular and perirenal haemorrhage with retroperitoneal haematoma in a patient with ovarian melanoma metastases.

A 47-year-old woman was admitted to our clinic for intensive pain in the left flank region. The transvaginal ultrasound showed a left adnexal solid mass with ascites. She had undergone surgical removal of skin melanoma in 2008, but in September 2019, intracardiac metastasis resulting from it had been discovered. CT performed in March 2020 had been negative for other metastases. A full abdomen ultrasound was not performed. During the night, the patient began to show signs and symptoms of hypovolaemic shock. The patient was urgently transferred to the operating room for a video laparoscopy. A vast left retroperitoneal haematoma was diagnosed along with voluminous enlargement of the left ovary. We proceeded with a left adnexectomy and blood transfusion. Subsequent contrast-enhanced CT revealed a left subcapsular, perirenal haematoma and a voluminous retroperitoneal haematoma. Kidney metastasis was also seen. The final histological diagnosis was metastatic amelanotic malignant melanoma of the ovary.

Melanoma oral amelanótico metastático com acometimento neurológico e gonadal em um cão fêmea - relato de caso / [Metastatic oral amelanotic melanoma with neurologic and gonadal involvement in a female dog - case report]

Relata-se um caso de melanoma oral disseminado em uma cadela de dois anos, com protrusão de bulbo ocular unilateral e quadro convulsivo progressivo. Os exames de imagem revelaram aumento de volume nas regiões submandibular, maxilar e cerebral, padrão nodular pulmonar e aumento das dimensões ovarianas. A citologia da massa submandibular indicou proliferação epitelial maligna, enquanto a biópsia excisional foi sugestiva de melanoma amelanótico. Na necropsia, havia uma massa gengival localmente infiltrativa e nodulações brancas nos linfonodos, nos rins, no pulmão, no cérebro e nos ovários, indicativas de metástase. O diagnóstico histopatológico consistiu de neoplasia maligna metastática indiferenciada, indicativo de melanoma amelanótico. Células caracterizadas por núcleo com cromatina espessa, múltiplos nucléolos bem evidentes, mitoses atípicas e multinucleações consistiram nos principais critérios de malignidade. No espaço peritrabecular ósseo facial, havia rara diferenciação pigmentar melanocítica, confirmada histoquimicamente pela técnica de Fontana-Massom e Giemsa. Algumas células foram positivas pela imuno-histoquímica para PNL-2 e Melan-A, e o diagnóstico de melanoma amelanótico disseminado foi firmado. A indiferenciação neoplásica marcante, com disseminação metastática multissistêmica e acometimento mútuo de sítios anatômicos pouco comuns, conjuntamente com a ampla variação dos padrões celulares, foi responsável pelo desafio diagnóstico do presente caso, ressaltando o papel decisivo da imuno-histoquímica para confirmação diagnóstica. A importância clínica deste trabalho consiste ainda em alertar a comunidade clínica e científica acerca da dificuldade diagnóstica, devendo-se considerar o melanoma amelanótico como diferencial mesmo em casos de lesões orais menos perceptíveis e/ou desprovidas de pigmentação.(AU)

A case of disseminated oral melanoma in a two year old female dog with unilateral protuberance of the eye bulb and progressive seizure is described. Imaging exams revealed increase of the submandibular, maxillary and cerebral regions, nodular pattern in lungs and increased ovarian dimensions. The cytology of the submandibular mass indicated a malignant epithelial proliferation, whereas the excisional biopsy indicated an amelanotic melanoma. At necropsy, a locally infiltrating gingival mass and white nodules in the lymph nodes, kidneys, lung, brain and ovaries were observed, indicative of metastases. Histopathological diagnosis consisted of an undifferentiated malignant metastatic neoplasm. Nucleus with coarse chromatin, prominent nucleoli, bizarre mitotic figures and multinucleated cells were the major malignant features. There was a poor melanocytic pigment differentiation in the peritrabecular space of facial bones, confirmed by Fontana-Masson and Giemsa histochemical techniques. Only a few cells were immunohistochemically positive for PNL-2 and Melan-A and the diagnosis of a disseminated amelanotic melanoma was performed. The diagnostic challenge was based on marked neoplastic undifferentiation, with multisystemic metastasis and mutual involvement of uncommon anatomic sites, associated with a large variability of cellular patterns, highlighting the decisive role of immunohistochemistry for diagnostic confirmation. Therefore, the clinical importance of this study is to warn the clinical and scientific community about the diagnostic challenge, considering the amelanotic melanoma as a differential even in cases of poorly apparent and/or nonpigmented oral lesions.(AU)

Amelanotic melanoma in a patient with oculocutaneous albinism.

Oculocutaneous albinism is a genetically heterogeneous, autosomal recessive group of disorders characterized by a generalized decreased or absence of melanin pigment in the eyes, hair, and skin. These patients have a greater sensitivity to UV radiation and a predisposition to skin tumors, mainly squamous cell carcinoma and basal cell carcinomas, and to a lesser extent malignant melanomas. Melanoma can be one of the most challenging cancers to diagnose in patients with albinism. We report an uncommon clinical presentation of melanoma, an amelanotic melanoma in the right supraciliar region in a patient with oculocutaneous albinism. The clinical presentation was an erythematous, scaly and ill-defined plaque. The skin biopsy revealed a lentigo maligna melanoma. Amelanotic melanomas are one of the two most difficult to diagnose subtypes of melanoma, together with the nevoid type. Melanoma in oculocutaneous albinism patients are often amelanotic, which makes their clinical diagnosis very difficult. These patients should be examined in the dermatology department at least once a year and it is recommended to have a high index of suspicion.

Amelanotic iris melanoma in a 7 year-old hispanic boy with subclinical globe perforation. / Melanoma amelanótico del iris en un niño hispano de 7 años con perforación del globo subclínica.

We report an unusual case of an amelanotic melanoma in a 7 year old hispanic child with subclinical globe perforation. Uveal melanoma rarely occurs in children. Young affected patients are mostly light-colored eye Caucasian adolescents. Since they are not common, these tumors are usually not recognized and misdiagnosed. Differential diagnoses and therapeutic options are outlined.

Amelanotic naevoid melanoma in a 16-month-old albino infant.

Melanoma in individuals with oculocutaneous albinism has been reported in the literature to be rare compared with the more common occurrence of squamous cell carcinoma and basal cell carcinoma. We present a singular case of amelanotic naevoid melanoma arising from a small congenital naevus in a 16-month old albino boy, the youngest reported to date.

Lesión melanocítica con patrón globular con cambios en el seguimiento a corto plazo / Melanocytic lesion with a globular pattern showing changes during short-term follow-up

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Un melanoma amelanótico con metástasis a la glándula tiroides. Descripción clinico-patológica de un caso / Amelanotic anorectal melanoma metastatic to the thyroid gland. A case report

A pesar de su rico aporte vascular, las metástasis en la glándula tiroides son eventos raros. Los carcinomas renales, colorectales, de pulmón y mama son las fuentes más frecuentes de metástasis. Presentamos el caso de una mujer de 75 años de edad, con el antecedente de un melanoma anorrectal amelanótico avanzado, operado un año antes, que se presentó con un crecimiento nodular rápido de la glándula tiroides, por lo que fue sometida a una tiroidectomía parcial. Histopatológicamente, el lóbulo tiroideo mostró una infiltración difusa por melanoma amelánico. Aunque se han publicado algunos casos de metástasis de melanoma en la glándula tiroides, la mayoría de ellos son de origen cutáneo por lo que, a nuestro entender, nosotros presentamos el primer caso de un melanoma anorrectal con metástasis a la glándula tiroide (AU)

Despite its rich vascular supply, metastases to the thyroid gland are rare. Renal, colorectal, lung and breast carcinomas are the most frequent sources of metastases. We report the case of a 75-year-old woman who presented with a rapid nodular enlargement of the thyroid gland, for which she underwent a partial thyroidectomy. She had a history of advanced amelanotic anorectal melanoma surgically treated one year previously. Histopathologically, the thyroid lobe showed diffuse infiltration by an amelanotic melanoma. Although a few cases of metastases of melanoma to the thyroid gland have been reported, the majority are derived from a cutaneous primary; to the best of our knowledge, this is the first reported case of an anorectal melanoma with metastasis to the thyroid gland (AU)

Primary malignant mucosal melanoma of the nasopharynx: an unusual cause of unilateral hearing loss.

There are many causes of unilateral hearing loss, and making the correct differential diagnosis, especially in elderly patients, is difficult. A primary malignant mucosal melanoma of the nasopharynx is extremely rare and can cause a variety of symptoms. Hearing loss, as a presenting symptom of mucosal malignant melanoma of the nasopharynx, has not yet been defined in the literature. Herein, we report a case of primary mucosal malignant melanoma of the nasopharynx presented with unilateral hearing loss in a 70-year-old man.

Primary amelanotic melanoma of the nasal cavity: a case report.

Primary mucosal malignant melanomas of the nose are rare, accounting for only 0.3 to 2% of all cases of malignant melanoma and about 4% of all head and neck melanomas. The amelanotic variant of mucosal malignant melanoma is even more rare, and the prognosis is poor. This variant usually arises in locations in which it is not noticeable, and therefore it is usually diagnosed at an advanced clinical stage when symptoms eventually manifest. We report a case of locally advanced amelanotic melanoma of the nasal cavity in a 55-year-old woman who presented with complaints of nasal obstruction and intermittent bleeding on the right side of the nose for 3 months and a gradually progressive diffuse swelling over the right periorbital and maxillary areas for 2 months with associated pain for 15 days. She was diagnosed with amelanotic melanoma on the basis of clinical, radiologic, and pathologic findings. In view of her advanced disease, she declined surgery and was treated with chemoradiotherapy, and she experienced a significant alleviation of her symptoms.

Acute small bowel obstruction due to intussusception of malignant amelonatic melanoma of the small intestine.

Malignant melanoma is a common malignancy and cutaneous melanoma showed an unusual prediction to metastasise into the small intestine. At autopsy metastatic deposits found in 50-60%, but less than 2-4% of melanoma patients diagnosed to have gastrointestinal (GI) metastasis during the disease course and 4-9% GI melanoma had unknown primary melanoma, which should be considered metastatic because primary lesion may be very small to diagnose or had regressed spontaneously. Few cases reported to have intussusception as a presenting feature. We report a case of amelanotic metastatic melanoma presented with intussusception and without known primary melanoma. The patient presented with abdominal pain, vomiting and distension. He was diagnosed as having acute intestinal obstruction as confirmed by erect abdominal x-ray. Ultrasonography showed small intestine intussusception. Emergency laparotomy revealed ilieo-ileal-type intussusception with intraluminal mass, which was resected and end-to-end anastomosis of bowel was performed. Histopathological and immunohistochemical examination of the resected specimen showed amelanotic melanoma.