Critérios histopatológicos para diagnóstico de melanoma maligno cutâneo: análise comparativa de sua freqüência em lesões benignas e melanomas de pequena espessura (< 2 mm)

INTRODUÇÃO: A histopatologia convencional continua sendo o padrão-ouro no diagnóstico dos melanomas cutâneos, apesar do progresso da imuno-histoquímica e da biologia molecular. Os critérios microscópicos existentes para esse diagnóstico são numerosos, porém nenhum deles é específico para se afirmar que uma determinada lesão é maligna quando ele está presente, ou é benigna na sua ausência. Alguns critérios têm uma relevância maior para o diagnóstico em relação a outros. OBJETIVO: Este estudo propõe uma análise daqueles critérios considerados mais importantes, comparando sua presença em lesões melanocíticas benignas e melanomas. MATERIAL E MÉTODOS: Foram estudadas 33 lesões melanocíticas benignas (nevo de Spitz: 13; nevo de Reed: 6; nevo displásico: 6; nevo congênito: 3; nevo adquirido: 3; nevo combinado: 1; nevo recorrente: 1), bem como 101 casos de melanomas extensivo/superficiais: 25 intra-epidérmicos e 76 invasivos de pequena espessura (< 2 mm). RESULTADOS: Alguns critérios mostraram alta freqüência em lesões benignas, apresentando pouca especificidade, enquanto outros tiveram menor positividade nas benignas, e alta freqüência nas malignas, mostrando sua maior especificidade e importância no diagnóstico dos melanomas. CONCLUSÃO: Os cinco critérios que mostraram diferenças estatisticamente significativas na comparação com as lesões benignas foram (em ordem decrescente de freqüência): 1. proliferação linear de células isoladas na camada basal; 2. início e fim da lesão com células isoladas; 3. melanócitos na camada granular; 4. disseminação pagetóide extensa; 5. nucléolos grandes, irregulares ou múltiplos. Os melanomas de pequena espessura não apresentam parte dos critérios considerados mais importantes, como falta de maturação, necrose e mitoses profundas.

Melanoma maligno cutâneo: sistema de pontos (scoring system) para auxílio no diagnóstico histopatológico

INTRODUÇÃO: O diagnóstico histopatológico de algumas lesões melanocíticas pode ser muito difícil, mesmo para especialistas, mas há casos em que a dificuldade surge pela inadequada e subjetiva aplicação dos critérios diagnósticos. OBJETIVO: O objetivo deste estudo é desenvolver um método de aplicação sistemática desses critérios, atribuindo valores para os mais importantes. MATERIAL E MÉTODOS: Selecionaram-se os critérios mais relevantes para o diagnóstico de melanoma, atribuindo valores de 1 a 5 de acordo com sua importância. Foram escolhidos 101 casos de melanomas de tipo extensivo-superficial com menos de 2mm de espessura para análise comparativa com 33 lesões melanocíticas benignas (13 nevos de Spitz, seis de Reed, seis displásicos, três congênitos, três adquiridos, um combinado e um recorrente). RESULTADOS: A soma dos valores dados aos critérios (score) apresentou diferença significativa entre lesões malignas e benignas, mostrando que esse método pode ser útil ao patologista cirúrgico generalista em sua rotina diária. CONCLUSÃO: A aplicação objetiva e sistemática dos critérios histopatológicos pelo sistema de pontos (scoring system) pode ajudar o diagnóstico diferencial entre maligno e benigno em muitas lesões, porém não tendo o efeito desejado nas lesões melanocíticas de comportamento biológico indeterminado.

Critérios anatomopatológicos para melanoma maligno cutâneo: análise qualitativa de sua eficácia e revisão da literatura

São bastante conhecidos pelos patologistas o desafio e a dificuldade que algumas lesões melanocíticas apresentam no momento de seu diagnóstico. A falta de uniformidade na maneira de aplicar os critérios diagnósticos é, sem dúvida, uma das causas principais dos altos índices de discordância descritos na literatura. O objetivo deste trabalho é tentar diminuir esta discordância e, para isso, foram selecionados os 12 critérios considerados mais importantes para o diagnóstico de melanoma: 1) tamanho; 2) simetria; 3) delimitação lateral; 4) maturação; 5) disseminação pagetóide; 6) necrose/ulceração; 7) infiltrado inflamatório; 8) regressão; 9) atipias celulares; 10) mitoses; 11) melanização; 12) proliferação de células isoladas. Foram expostas as características de cada um deles e sua aplicação no diagnóstico dos melanomas, lembrando sempre as possíveis exceções, onde estes critérios podem estar presentes em lesões melanocíticas benignas. Posteriormente, em três tabelas, estabeleceu-se o diagnóstico diferencial entre melanoma e três condições melanocíticas benignas que costumam apresentar maiores dificuldades no diagnóstico diferencial. Como nenhum critério deve ser considerado isoladamente, a aplicação rigorosa do conjunto de dados aqui fornecido pode ajudar substancialmente o patologista cirúrgico generalista (não-especialista em lesões melanocíticas) a resolver alguns problemas na sua rotina diária.

Clinical, dermoscopic and histopathological evaluation of the Meyerson nevus - Case report

Meyerson nevi occur whenever a rare focal and transitory eczematous eruption arises around melanocytic lesions. The same phenomenon has also been observed in non-melanocytic lesions as well. Herein we report the case of a 25 year old, male patient, who had noticed, two months before, the arising of a pruriginous and erithematous halo around two nevi localized on his abdomen. The lesions were found to be atypical on dermoscopic examination and he was submitted to surgical excision of both nevi. Histopathological examination revealed displastic compound melanocytic nevi, surrounded by intraepidermical vesicles and spongiosis. Present report suggests that Meyerson phenomenon does not seem to alter dermoscopic features of nevi.

Heritability and gene-environment interactions for melanocytic nevus density examined in a U.K. adolescent twin study

Risk factors for melanoma include environmental (particularly ultraviolet exposure) and genetic factors. In rare families, susceptibility to melanoma is determined by high penetrance mutations in the genes CDKN2A or CDK4, with more common, less penetrant genes also postulated. A further, potent risk factor for melanoma is the presence of large numbers of melanocytic nevi so that genes controlling nevus phenotype could be such melanoma susceptibility genes. A large Australian study involving twins aged 12 y of predominantly U.K. ancestry showed strong evidence for genetic influence on nevus number and density. We carried out essentially the same study in the U.K. to gain insight into gene-environment interactions for nevi. One hundred and three monozygous (MZ) and 118 dizygous (DZ) twin pairs aged 10-18 y were examined in Yorkshire and Surrey, U.K. Nevus counts were, on average, higher in boys (mean = 98.6) than girls (83.8) (p = 0.009) and higher in Australia (110.4) than in the U.K. (79.2, adjusted to age 12 y, p < 0.0001), and nevus densities were higher on sun-exposed sites (92 per m(2)) than sun-protected sites (58 per m(2)) (p < 0.0001). Correlations in sex and age adjusted nevus density were higher in MZ pairs (0.94, 95% CI 0.92-0.96) than in DZ pairs (0.61, 95%CI 0.49-0.72), were notably similar to those of the Australian study (MZ = 0.94, DZ = 0.60), and were consistent with high heritability (65% in the U.K., 68% in Australia). We conclude that emergence of nevi in adolescents is under strong genetic control, whereas environmental exposures affect the mean number of nevi.

Linkage and Association Analysis of Radiation Damage Repair Genes XRCC3 and XRCC5 with Nevus Density in Adolescent Twins

Previous studies have shown that a deficiency in DNA damage repair is associated with increased cancer risk, and exposure to UV radiation is a major risk factor for the development of malignant melanoma. High density of common nevi (moles) is a major risk factor for cutaneous melanoma. A nevus may result from a mutation in a single UV-exposed melanocyte which failed to repair DNA damage in one or more critical genes. XRCC3 and XRCC5 may have an effect on nevus count through their function as components of DNA repair processes that may be involved directly or indirectly in the repair of DNA damage due to UV radiation. This study aims to test the hypothesis that the frequency of flat or raised moles is associated with polymorphism at or near these DNA repair genes, and that certain alleles are associated with less efficient DNA repair, and greater nevus density. Twins were recruited from schools in south eastern Queensland and were examined close to their 12th birthday. Nurses examined each individual and counted all moles on the entire body surface. A 10cM genome scan of 274 families (642 individuals) was performed and microsatellite polymorphisms in XRCC3 and adjacent to XRCC5 were also typed. Linkage and association of nevus count to these loci were tested simultaneously using a structural-equation modeling approach implemented in MX. There is weak evidence for linkage of XRCC5 to a QTL influencing raised mole count, and also weak association. There is also weak evidence for association between flat mole count and XRCC3. No tests were significant after correction for testing multiple alleles, nor were any of the tests for total association significant. If variation in XRCC3 or XRCC5 influences UV sensitivity, and indirectly affects nevus density, then the effects are small.

Vascular Malformation and Common Keratinocytic Nevus of the Soft Type: Phacomatosis Pigmentovascularis Revisited

Phacomatosis pigmentovascularis is a rare syndrome characterized by the coexistence of a pigmented nevus and a cutaneous vascular malformation. We report a 5-year-old boy with all the typical findings of phacomatosis pigmentovascularis type Ia. Although its existence according to the traditional classification has been questioned, this case represents a very rare association of a capillary vascular malformation and a common keratinocytic nevus of the soft type.

Blue rubber bleb nevus syndrome

The blue rubber nevus syndrome consists of multiple venous malformations in the skin and gastrointestinal tract associated with intestinal hemorrhage and iron deficiency anemia. Other organs may be involved. The causes of this syndrome are unknown. Its most common presentation is in the form of sporadic cases, but dominant autosomal inheritance has been described. It is a condition that affects both sexes equally, and its occurrence is rare in the black race. We present a case of this syndrome diagnosed in a 11-year-old patient. He had severe anemia and a venous swelling on the trunk. Similar lesions were found in the stomach, bowel, and on his foot. We emphasize the main clinical aspects: intestine, eyes, nasopharynx, parotids, lungs, liver, spleen, heart, brain, pleura, peritoneum, pericardium, skeletal muscles, bladder, and penis lesions, systemic complications that may occur to these patients which are thrombosis and calcification, as well as consumptive coagulopathy and thrombocytopenia that may occur within the nevi.

Blue rubber bleb nevus syndrome: case report

The case of a patient with blue rubber bleb nevus syndrome who is infected by acquired immunodeficiency syndrome virus due to multiple blood transfusions is presented. This case shows that although it is a rare systemic disorder, blue rubber bleb nevus syndrome has to be considered in the differential diagnosis of chronic anemia or gastrointestinal bleeding. Patients should be investigated by endoscopy, which is the most reliable method for detecting these lesions. The patient underwent gastroscopy and enteroscopy via enterotomy with identification of all lesions. Minimal resection of the larger lesions and string-purse suture of the smaller ones involving all the layers of the intestine were performed. The string-purse suture of the lesions detected by enteroscopy proved to be an effective technique for handling these lesions, avoiding extensive intestinal resection and stopping the bleeding. Effective management of these patients demands aggressive treatment and should be initiated as soon as possible to avoid risks involved in blood transfusions, as occurred in this case.

Large agminated cellular 'plaque-type' blue nevus surrounding the ear: a case and review.

Large or giant cellular blue nevi are usually congenital and represent a challenge for the physician. Close anatomic structures may be altered by the size of the moles. In this article, we report the case of an uncommon large, agminated, cellular blue nevus of the 'plaque type' in a 42-year-old female. Due to the risks of malignant melanoma development on a large or giant blue nevus, we highlight the importance of proper histopathological diagnosis. Furthermore, because of the possibility that the nevus may invade the bone and cerebral tissues, we discuss the indication of a radiological diagnosis. The accurate correlation to clinical and histopathological findings and appropriate multidisciplinary management can save the lives of patients. © 2013 S. Karger AG, Basel.

Naevus du repli semi-lunaire de la conjonctive de découverte tardive [Conjunctival semi-lunar fold nevus of presumed late onset].

Conjunctival nevi are lesions observed commonly occasionnally and can be found later in a life. Such a lesion was observed on the conjunctival semilunar fold in a 76-year-old female patient. It was oval in shape, pigmented, and was mainly visible when the affected eye was in abduction. As no accurate anterior clinical history was available, surgical resection was performed. Hitopathological study disclosed a subepithelial nevus, which was completely resected. Regular follow-up was recommended, as is usual after surgical resection of a conjunctival pigmented tumor.

Association naevus et papillome de la caroncule. A propos d'un cas observation anatomo-clinique [Papillomatous and nevus of the caruncle].

A 63-year-old male patient was operated of a single conjunctival papillomatous lesion located on the left caruncle. The curative tumoral excision was followed by its histological analysis. Histologically, the tumor associated an epithelial squamous papilloma with a subepithelial nevus, confirming a combination of two different lesions.

Naevus naevocellulaire achrome palpébral prenant l'aspect d'un carcinome basocellulaire [Nevus mimicking a basal cell carcinoma of the eyelid].

A clinicopathologic case of a 41-year-old female patient exhibited a single cutaneous tumor at the inner part of the free margin of the inferior left eyelid. It was a pink, fleshy, and nodular well-circumscribed exophytic mass with thin vessels on its surface. Experienced already for 20 years, this lesion had been observed 6 years before and has not exhibited much change since then. However, its clinical appearance argued for a possible small basal cell carcinoma, which had grown over the inferior left lachrymal duct. After surgical removal, histopathology showed that the tumor was an amelanotic dermal nevus. No disturbance of lachrymal drainage was observed after surgery. This case shows that nodular amelanotic tumors of the eyelid, even when located on the inner segment of the eyelid, may be a nevus.