Abstract Viruses have been frequently identified in several human neoplasms, but the etiological role of these viruses in some tumors is still a matter of controversy. Polyomaviruses stand out among the main viruses with oncogenic capacity, specifically the Merkel cell polyomavirus (MCPyV). Recent revisions in the taxonomy of polyomaviruses have divided the Polyomaviridae family into six genera, including 117 species, with a total of 14 currently known human-infecting species. Although the oncogenicity of polyomaviruses has been widely reported in the literature since 1950, the first description of a polyomavirus as an etiological agent of a neoplasm in humans was made only in 2008 with the description of MCPyV, present in approximately 80% of cases of Merkel cell carcinoma (MCC), with the integration of its genome to that of the tumor cells and tumor-specific mutations, and it is considered the etiological agent of this neoplasm since then. MCPyV has also been detected in keratinocyte carcinomas, such as basal cell carcinoma and squamous cell carcinoma of the skin in individuals with and without immunosuppression. Data on the occurrence of oncogenic viruses potentially involved in oncogenesis, which cause persistence and tissue injury, related to the Merkel cell polyomavirus are still scarce, and the hypothesis that the Merkel cell polyomavirus may play a relevant role in the genesis of other cutaneous carcinomas in addition to MCC remains debatable. Therefore, the present study proposes to explore the current knowledge about the presence of MCPyV in keratinocyte carcinomas.

RESUMO Adenodermatofibroma hemossiderótico é uma lesão recentemente conhecida, caracterizada por um nódulo dérmico com estruturas císticas de uma glândula apócrina, circundado por um estroma do tipo dermatofibroma com macrófagos hemossideróticos. Apresentamos o primeiro relato de caso dessa entidade no Brasil junto a imagens representativas, além de uma revisão do assunto e discussões sobre a origem apócrina dessa lesão.

ABSTRACT Hemosiderotic adenodermatofibroma is a recently recognized lesion, characterized by a dermal nodule with cystic structures of an apocrine gland, surrounded by a dermatofibroma-like stroma with hemosiderotic macrophages. We present the first case report of this entity in Brazil together with representative images, in addition to a review on the subject and discussion about the apocrine origin of this lesion.

RESUMEN El dermatoadenofibroma hemosiderótico es una lesión recientemente descrita, caracterizada por un nódulo dérmico con estructuras quísticas de una glándula apocrina, rodeado por un estroma del tipo dermatofibroma con macrófagos hemosideróticos. Presentamos el primer reporte de caso de esa entidad en Brasil, junto a imágenes representativas, además de una revisión del tema y discusiones acerca del origen apocrina de esa lesión.

Resumo A linfohistiocitose hemofagocítica (LHH) é uma condição incomum e potencialmente fatal, caracterizada por importante ativação imunológica e produção maciça de citocinas por células mononucleares inflamatórias, devido a defeitos na função linfocitária citotóxica. É ainda mais incomum em receptores de transplante renal, nos quais está freqüentemente associada a infecções não controladas. A mortalidade da LHH é alta, e o diagnóstico diferencial com sepse é um desafio. A abordagem e o tratamento dependem do gatilho e das comorbidades subjacentes. Relatamos o caso de uma paciente transplantada renal com 50 anos de idade, admitida com febre e mal-estar 3 meses após o transplante, apresentando anemia, febre, hipertrigliceridemia, níveis elevados de ferritina sérica e antigenemia positiva para CMV. A urina mostrou positividade para células decoy e BKV-DNA. A biopsia do enxerto mostrou nefrite por CMV. Ambas as culturas de sangue e urina foram positivas para E. coli. A hemofagocitose foi confirmada pelo aspirado de medula óssea. A imunossupressão foi reduzida e a paciente recebeu altas doses de imunoglobulina intravenosa e dexametasona, com resposta completa após 3 semanas. Destaca-se a importância do diagnóstico precoce e do manejo adequado de uma condição rara e grave em um paciente transplantado renal, o que pode permitir um curso clínico favorável e melhorar a taxa de sobrevida.

Abstract Hemophagocytic lymphohistiocytosis (HLH) is an uncommon and life-threating condition characterized by major immune activation and massive cytokine production by mononuclear inflammatory cells, due to defects in cytotoxic lymphocyte function. It is even more unusual in renal transplant recipients, in which it is often associated with uncontrolled infection. The mortality is high in HLH and differential diagnosis with sepsis is a challenge. The approach and management depend on the underlying trigger and comorbidities. We report a case of a 50-year-old renal transplant female admitted with fever and malaise 3 months post-transplant and presenting anemia, fever, hypertriglyceridemia, high levels of serum ferritin, and positive CMV antigenemia. Urine was positive for decoy cells and BKV-DNA. Graft biopsy showed CMV nephritis. Both blood and urine cultures where positive for E. coli. Hemophagocytosis was confirmed by bone marrow aspiration. Immunosuppression was reduced, and the patient received high-dose intravenous immunoglobulin and dexamethasone, with complete response after 3 weeks. We highlight the importance of early diagnosis and proper management of a rare and serious condition in a renal transplant patient, which can allow a favorable clinical course and improve survival rate.

Abstract: The diagnosis of cutaneous melanoma in situ, considered to have excellent prognosis, has been increasingly frequent, with rare isolated reports of cutaneous melanoma in situ presenting recurrence, metastasis, and death. No specific study is found in the literature about these lesions of unexpected behavior. We describe the demographic and histopathological findings of 448 cases of cutaneous melanoma in situ in 369 patients, emphasizing the prognostic criteria of those with unfavorable outcomes, corresponding to 9 cases in which regression had no significant role. Adnexotropism was found in 44.5% of cases. The study of early lesions would allow clinicians to have a better understanding of the evolutionary processes of the disease.

Abstract: Myeloid sarcoma is an extramedullary tumor of malignant myeloid cells often associated with acute myeloid leukemia, chronic myeloproliferative disorders and myelodysplastic syndromes. The skin is one of the most commonly affected sites. We report a rare case of cutaneous myeloid sarcoma associated with chronic myeloid leukemia.

Abstract: Skin metastases are relatively rare and occur most often when the cancer is already advanced, invading other organs. As to location, they often seem to elect areas located close to the primary tumor, although distant sites, such as the scalp, may be affected with some frequency. We present a case of a 76-year-old woman with colon adenocarcinoma that had a single metastatic lesion on the scalp.

RESUMO O diagnóstico de lesões melanocíticas pode ser desafiador, e o estudo imuno-histoquímico é uma ferramenta valiosa para os dermatopatologistas. Relatamos dois casos inicialmente diagnosticados como melanoma in situ, avaliando os achados histopatológicos e imuno-histoquímicos e os casos publicados na literatura com resultados semelhantes. Ressaltamos a importância da correlação clinicopatológica na avaliação das lesões com danos na interface e nos "ninhos pseudomelanocíticos", que podem simular melanoma in situ. Destacamos também a importância da utilização de um painel de imuno-histoquímica, além do Melan-A, no estudo dessas lesões.

ABSTRACT The diagnosis of melanocytic lesions can be challenging and immunohistochemical study is a valuable tool for dermatopathologists. We report two cases initially simulating melanoma in situ, reviewing the histopathological and immunohistochemical findings and the cases published in the literature with similar findings/results. We emphasize the importance of clinicopathological correlation in the evaluation of lesions with interface changes and in the "pseudomelanocytic nests", which may simulate melanoma in situ. We also highlight the importance of using a immunohistochemistry panel in addition to Melan-A, in the study of these lesions.

Spitz nevus is a benign melanocytic lesion and also one of the main differential diagnosis of melanoma. A descriptive and retrospective study of surgical specimens from patients with a diagnosis of Spitz nevus was conducted at two institutions in Niterói - RJ. 32 cases were analyzed. The most frequent histological subtype was compound (60 %), with a predominance of epithelioid cells (17 cases - 53%). Pagetoid spread was observed in 21 cases (68%). Maturation of melanocytes was present in 13 cases (81%). Kamino bodies were found in eight cases (25%). Atypical melanocytes were present in 18 cases (56%). Mitoses were present in 11 cases (34%). Detailed knowledge of the classical form of Spitz nevi is essential for the differential diagnosis with melanoma. However, no single criterium is definitive in the differential diagnosis between Spitz nevus and melanoma.

A fasciíte nodular é um tumor benigno, decorrente da proliferação reativa de células fibroblásticas ou miofibroblásticas. Pode ser confundida com os sarcomas, devido a seu rápido crescimento e rica celularidade. Apesar da possibilidade da involução espontânea, a excisão é o tratamento de escolha. É apresentada uma paciente de 24 anos, com um nódulo de 3 meses de evolução na região zigomática. Foi realizada biópsia excisional. O exame histopatológico associado à imuno-histoquímica com os marcadores HHF35, AML e Ki-67 permitiram a confirmação diagnóstica. A principal relevância do caso apresentado é sua rara localização, sugerindo a sua inclusão entre os diagnósticos diferenciais das lesões tumorais na face.

Nodular fasciitis is a benign tumor, resulting from reactive proliferation composed of fibroblastic/myofibroblastic cells. Due to its rapid growth and high cellularity it may be mistaken for sarcoma. Despite the possibility of spontaneous regression, excision is the treatment of choice. A 24-year-old female patient presented with a nodule on the zygomatic region with 3 months of evolution. Excisional biopsy was performed. Histopathological examination associated with immunohistochemical markers HHF35, AML and Ki-67 allowed diagnostic confirmation. The main relevance of the case presented is its rare location, suggesting its inclusion among the differential diagnoses of tumor lesions on the face.

Síndrome stiff skin é doença rara, esclerodermiforme, de etiologia desconhecida, caracterizada por endurecimento pétreo da pele, hipertricose leve e limitação da mobilidade articular. Não há tratamento efetivo até o momento. Exercícios e reabilitação são importantes para manter a qualidade de vida do paciente. Os autores apresentam caso de um menino de dois anos de idade com endurecimento cutâneo progressivo desde os oito meses de idade e restrição secundária da mobilidade articular, diagnosticado como Síndrome stiff skin

Stiff skin syndrome is a rare scleroderma-like disorder of unknown etiology characterized by stone-hard indurations of skin, mild hypertrichosis and limited joint mobility. No effective treatment has yet been found. Exercises and rehabilitative therapy are important in maintaining the patient's quality of life. The authors present a case of a two-year-old boy with progressive skin hardening since he was eightmonth old and secondary restricted joint mobility, diagnosed as Stiff skin syndrome

FUNDAMENTOS: A síndrome de Sweet corresponde a um conjunto de alterações cutâneas, sistêmicas e histopatológicas como resposta a diversos estímulos, semelhantes ao eritema nodoso, ao eritema multiforme e à vasculite leucocitoclásica. São descritas condições associadas como infecção, gravidez, uso de drogas e malignidades. OBJETIVOS: Avaliar as alterações clínicas e histopatológicas da síndrome, relacionando-a a outras condições. MÉTODO: Estudo retrospectivo de 73 casos com avaliação microscópica de lesões cutâneas, dados clínicos e laboratoriais. RESULTADOS: Houve predomínio de mulheres (83,0%), brancas (49,2%), entre a quarta e a sexta décadas de vida (73,8%). Placas eritematosas (76,9%), pápulas (43,0%), pseudovesiculação (PV) (38,4%) e lesões em alvo (18,5%) foram as principais alterações. Entre as condições associadas, infecções de vias aéreas (15,4%) e uso de drogas (10,8%) foram as mais frequentes. Outras associações, representadas por um caso cada, foram: linfoma de Hodgkin, gravidez, colite ulcerativa, policitemia vera e lúpus eritematoso em paciente com Aids. Neutrófilos com leucocitoclasia (98,6%), degeneração do colágeno (87,7%), edema (74,0%) e PV (38,4%) foram os principais achados microscópicos. Eosinófilos estiveram presentes (41,1%) de raros a abundantes e, em geral, não relacionados ao uso de drogas. O infiltrado inflamatório atingiu a derme profunda em 47,9% das vezes e encontrou-se paniculite em 80,0% dos casos nos quais a hipoderme estava representada (10 casos). CONCLUSÕES: Os achados, de modo geral, coincidem com os da literatura, destacando-se: frequente participação de eosinófilos sem correlação com a ingestão de medicamentos, paniculite e rara associação com linfoma de Hodgkin, sendo este o quinto relato de tal ocorrência, segundo o conhecimento dos autores.

BACKGROUND: Sweet's syndrome refers to a set of cutaneous, systemic and histopathological alterations that occur in response to different stimuli, in a similar way to that occurring in erythema nodosum, erythema multiforme and leukocytoclastic vasculitis. The syndrome has been described in association with conditions such as infections, pregnancy, the use of certain medications and malignancy. OBJECTIVES: To evaluate the clinical and histopathological alterations occurring in this syndrome and to assess the association between these alterations and other conditions. METHODS: A retrospective study of 73 cases was conducted, evaluating data on the microscopic examination of skin lesions, as well as clinical and laboratory data. RESULTS: The majority of the patients were female (83.0%), white (49.2%) and between 30 and 60 years of age (73.8%). The principal alterations found were: erythymatous plaques (76.9%), papules (43.0%), pseudo-vesiculation (PV) (38.4%) and target lesions (18.5%). With respect to the associated conditions, upper respiratory tract infections (15.4%) and the use of medication (10.8%) were the most common. Other associations, albeit represented by only one case each, were: Hodgkin's lymphoma, pregnancy, ulcerative colitis, polycythemia vera and lupus erythematosus in a patient with acquired immune deficiency syndrome (AIDS). The principal microscopic findings were: neutrophils with leukocytoclasia (98.6%), collagen degeneration (87.7%), edema (74.0%) and PV (38.4%). The presence of eosinophils (41.1%) ranged from rare to abundant and was usually unrelated to the use of medication. Inflammatory infiltrate reached the deep epidermal layer in 47.9% of cases and panniculitis was found in 80.0% of cases in which the hypodermis was affected (10 cases). CONCLUSIONS: In general, these findings are in agreement with results published in the literature, emphasizing the frequent finding of eosinophils unrelated to drug use, panniculitis and the rare association with Hodgkin's lymphoma. This is the fifth report of an association between Sweet's syndrome and Hodgkin's disease.

Calcinose cutânea é uma doença incomum, de fisiopatologia incerta e, muitas vezes, incapacitante. Caracteriza-se pela deposição de sais de cálcio na pele ou tecido subcutâneo. É classificada em quatro subtipos: metastática, distrófica, idiopática e iatrogênica. Pode ser vista em várias doenças sistêmicas como hiperparatireoidismo e hipervitaminose D, ocorrendo com maior frequência na dermatomiosite, esclerodermia e síndromes overlap, sendo uma complicação infrequente no lúpus eritematoso sistêmico. O manejo das complicações secundárias, assim como o sucesso terapêutico, constituem desafios constantes no seguimento destes casos.

Calcinosis cutis is an uncommon disease of unclear pathophysiology that is often disabling. It is characterized by the formation of calcium deposits in the skin or subcutaneous tissue. It is classified into four subtypes: dystrophic, metastatic, idiopathic or iatrogenic. It may be seen in a variety of systemic diseases such as hyperparathyroidism and hypervitaminosis D, but is most commonly found in dermatomyositis, scleroderma and overlap syndromes and is a rare complication of systemic lupus erythematosus. The management of secondary complications and the success of therapy are constant challenges in the follow-up of these cases.

INTRODUÇÃO: O diagnóstico de melanomas cutâneos finos (MCF) é cada vez mais freqüente. Essas lesões, inicialmente associadas a excelente prognóstico, têm apresentado recidiva ou metástases e, às vezes, óbito. Muitas variáveis têm sido estudadas e, embora nenhuma delas tenha esclarecido tal comportamento, a regressão e seu possível impacto negativo têm merecido atenção. A regressão tardia é referida pelos autores como de maior relevância no prognóstico. OBJETIVO: Correlacionar a espessura máxima da área de regressão dos MCFs com o tempo de sobrevida livre de doença. MATERIAL E MÉTODO: Estudo retrospectivo de 84 casos de MCF. Foram utilizados os critérios de Kang et al.(18) para identificação e classificação evolutiva (recente, intermediária e tardia) da regressão. RESULTADOS: Nos 84 MCFs estudados, regressão (em qualquer fase) foi observada em 70 (83,3%), sendo 30 casos (35,7%) com regressão tardia. A medida máxima da regressão variou entre 0,16 e 1,53 mm. O tempo de sobrevida livre de doença variou entre 17 dias e 108 meses. Cinco casos (5,9%) evoluíram de forma desfavorável, dos quais três eram melanomas in situ (MIS). Não houve correlação entre as variáveis estudadas (p > 0,05). DISCUSSÃO: O significado da regressão sobre o comportamento de MCF é controverso, provavelmente devido a diferentes metodologias utilizadas nos poucos estudos realizados sobre o tema e à grande variabilidade no tamanho e na composição das amostras. Não há consenso na literatura sobre um sistema padronizado de medição da regressão, o que explica, em parte, os resultados controversos obtidos até o momento. CONCLUSÃO: Não ficou demonstrada relação entre a espessura da regressão nos melanomas finos e o tempo de sobrevida livre de doença. Estudos futuros, com amostra maior, poderão contribuir para a elucidação da natureza deste fenômeno.

BACKGROUND: The diagnosis of thin cutaneous malignant melanomas has been increasingly more frequent. These lesions, initially associated with excellent prognosis, have presented recurrence or metastases and sometimes have been fatal. Many variables have been studied and, although none of them has explained this behaviour, regression and its possible negative impact have been focused on recently. According to some authors, late regression bears major relevance in the prognosis. OBJECTIVE: To correlate the maximum regression thickness of thin cutaneous malignant melanomas with disease-free survival time. MATERIALS AND METHOD: Retrospective study of 84 cases of thin cutaneous malignant melanomas. The criteria of Kang et al. (1993) for identification and evolutionary classification (early, intermediate and late) of the regression were applied. RESULTS: Regression (in any phase) was observed in 70 out of 84 thin cutaneous malignant melanomas (83.3%), and 30 cases (35.7%) showed late regression. The maximum regression thickness measurement ranged from 0.16 to 1.53 mm. Disease-free survival time ranged from 17 days to 108 months. Five cases (5.9%) had an unfavorable outcome, from which three were in situ melanomas. There was no correlation between the studied variables (p > 0.05). DISCUSSION: The meaning of regression in thin cutaneous malignant melanomas is controversial, probably due to the different methods applied in the few studies carried out about the subject and the wide variety of size and composition of the samples. There is no medical consensus as to a standardized regression measurement system, which partially explains the controversial results obtained to date. CONCLUSIONS: There was no statistical correlation between regression thickness in thick cutaneous melanomas and disease-free survival time (p > 0.05). Future studies with wider samples may contribute to a better understanding of this phenomenon.