OBJECTIVES: We investigated four components of the Wnt signaling pathway in medulloblastomas. Medulloblastoma is the most common type of malignant pediatric brain tumor, and the Wnt signaling pathway has been shown to be activated in this type of tumor. METHODS: Sixty-one medulloblastoma cases were analyzed for β-catenin gene (CTNNB1) mutations, β-catenin protein expression via immunostaining and Wnt signaling pathway-related gene expression. All data were correlated with histological subtypes and patient clinical information. RESULTS: CTNNB1 sequencing analysis revealed that 11 out of 61 medulloblastomas harbored missense mutations in residues 32, 33, 34 and 37, which are located in exon 3. These mutations alter the glycogen synthase kinase-3β phosphorylation sites, which participate in β-catenin degradation. No significant differences were observed between mutation status and histological medulloblastoma type, patient age and overall or progression-free survival times. Nuclear β-catenin accumulation, which was observed in 27.9% of the cases, was not associated with the histological type, CTNNB1 mutation status or tumor cell dissemination. The relative expression levels of genes that code for proteins involved in the Wnt signaling pathway (CTNNB1, APC, AXIN1 and WNT1) were also analyzed, but no significant correlations were found. In addition, large-cell variant medulloblastomas presented lower relative CTNNB1 expression as compared to the other tumor variants. CONCLUSIONS: A small subset of medulloblastomas carry CTNNB1 mutations with consequent nuclear accumulation of β-catenin. The Wnt signaling pathway plays a role in classic, desmoplastic and extensive nodularity medulloblastoma variants but not in large-cell medulloblastomas.

Objetivo: Relatar o primeiro caso de forma infantil da doença de Pompe tratado no Brasil. Descrição: Trata-se de doença de depósito lisossomal que se caracteriza por defeitos da enzima alfa-glicosidase ácida, com acúmulo intracelular de glicogênio, principalmente nos músculos. São descritas a forma infantil e tardia. Desde 2006, está disponível tratamento com enzima recombinante humana. Descreve-se o primeiro caso de forma infantil da doença tratado no Brasil. Trata-se de menina com 2,5 meses de idade e progressão rápida da doença, com perda dos movimentos dos membros, miocardiopatia hipertrófica e insuficiência respiratória aos 7 meses de idade. Após 10 meses de tratamento, apresentou boa resposta clínica, com remissão da insuficiência respiratória, recuperação parcial dos movimentos dos membros e melhora importante do quadro cardiológico. Comentários: Apesar de pouco freqüente, a forma infantil da doença de Pompe é letal. A disponibilidade de tratamento eficaz aumenta a necessidade de conhecimento e diagnóstico precoce da doença.

Objective: To describe the first case of infantile Pompe disease to be treated in Brazil. Description: Pompe disease is a glycogen storage disease related to defects in the acid alpha-glucosidase enzyme, leading to an intracellular accumulation of glycogen, mainly in muscles. Two forms are described: infantile and juvenile. Since 2006, treatment with recombinant human acid alpha-glucosidase has been available. This article describes the first case of infantile Pompe disease treated in Brazil. A girl presented at 2.5 months of age with rapid disease progression, exhibiting severe hypotonia, loss of movements in both upper and lower limbs and hypertrophic cardiomyopathy, progressing to respiratory failure by the age of 7 months. After 10 months of treatment, she exhibited a good clinical response, with remission of the respiratory failure, partial recovery of arm and leg movements and improvement of cardiologic condition. Comments: Despite its low incidence, infantile Pompe disease is lethal. The availability of an effective treatment has created an urgent need to improve knowledge and early diagnosis of this disease.

OBJETIVO: Identificar fatores de risco associados à calcinose em crianças e adolescentes com dermatomiosite juvenil. MÉTODOS: Prontuários de 54 pacientes com dermatomiosite juvenil foram estudados. Foram avaliados dados demográficos; características clínicas: grau de força muscular (I a V do Medical Research Council), presença de comprometimentos pulmonar (distúrbio ventilatório restritivo com presença ou ausência do anticorpo anti-Jo-1), gastrointestinal (refluxo gastroesofágico) e cardíaco (pericardite e/ou miocardite); exames laboratoriais: elevação de enzimas musculares (creatinoquinase, aspartato aminotransferase, alanina aminotransferase e desidrogenase lática) e terapias utilizadas: corticoterapia isolada ou associada à cloroquina e/ou imunossupressor. Os pacientes foram divididos em dois grupos de acordo com a presença ou ausência de calcinose e foram avaliados através de análise univariada e multivariada. RESULTADOS: Calcinose foi evidenciada em 23 (43%) pacientes, sendo em seis (26%) antes do diagnóstico e em 17 (74%) após. A análise univariada revelou que comprometimentos cardíaco (p = 0,01) e pulmonar (p = 0,02) e necessidade da utilização de um ou mais imunossupressores (metotrexato, ciclosporina A e/ou pulsoterapia com ciclofosfamida endovenosa) no tratamento da dermatomiosite juvenil (p = 0,03) foram associados com uma maior incidência de calcinose. A análise multivariada mostrou que comprometimento cardíaco (OR = 15,56; IC95% 1,59-152,2) e uso de um ou mais imunossupressores (OR = 4,01; IC95% 1,08-14,87) foram as únicas variáveis independentes associadas à presença de calcinose. CONCLUSÕES: O aparecimento da calcinose foi freqüente na dermatomiosite juvenil, habitualmente na evolução da doença. A calcinose foi associada aos casos mais graves, que apresentaram envolvimento cardíaco e necessitaram da utilização de imunossupressores no seu tratamento.

OBJECTIVE: To identify risk factors associated with calcinosis in children and adolescents with juvenile dermatomyositis. METHODS: A review was carried out of the medical records of 54 patients with juvenile dermatomyositis. Data were collected on demographic characteristics, clinical features: muscle strength (stages I to V of the Medical Research Council scale), pulmonary involvement (restrictive pulmonary disease with presence or absence of anti-Jo1 antibodies), gastrointestinal problems (gastroesophageal reflux) and/or heart disease (pericarditis and/or myocarditis); laboratory tests: elevated muscle enzyme levels in serum (creatine phosphokinase, aspartate aminotransferase, alanine aminotransferase and/or lactate dehydrogenase); and on the treatments given: corticoid therapy in isolation or associated with hydroxychloroquine and/or immunosuppressants. The patients were divided into two groups, depending on presence or absence of calcinosis and data were evaluated by both univariate and multivariate analyses. RESULTS: Calcinosis was identified in 23 (43%) patients, and in six (26%) patients it had emerged prior to diagnosis while in 17 (74%) it was post diagnosis. The univariate analysis revealed that cardiac (p = 0.01) and pulmonary (p = 0.02) involvement and the need for one or more immunosuppressor (methotrexate, cyclosporine A and/or pulse therapy with intravenous cyclophosphamide) to treat juvenile dermatomyositis (p = 0.03) were all associated with an increased incidence of calcinosis. The multivariate analysis then demonstrated that only cardiac involvement (OR = 15.56; 95%CI 1.59-152.2) and the use of one or more immunosuppressor (OR = 4.01; 95%CI 1.08-14.87) were independently associated with the presence of calcinosis. CONCLUSIONS: Calcinosis was a frequent development among these juvenile dermatomyositis cases, generally emerging as the disease progressed. Calcinosis was associated with the more severe cases that also had cardiac involvement and where immunosuppressors had to be included in the treatment.

A dermatomiosite (DM) em adultos está freqüentemente associada com câncer. Já na faixa etária pediátrica, a dermatomiosite juvenil (DMJ) é predominantemente idiopática, e sua associação com neoplasia é rara e com base apenas em relatos de casos. Embora rara, a presença de neoplasia em pacientes com DMJ deve ser sempre suspeitada quando houver manifestações clínicas atípicas e alterações laboratoriais incomuns. A seguir, descrevemos e discutimos um caso de DMJ e linfoma de Hodgkin em uma adolescente.

Dermatomyositis (DM) in adults is frequently associated with cancer. In contrast, during childhood juvenile dermatomyositis (JDM) is predominantly idiopathic and its association with neoplasia is rare and based only in case reports. Although rare, the presence of neoplasia in JDM patients must always be suspected in face of atypical clinical manifestations and uncommon laboratorial findings. We describe and discuss a case of JDM and Hodgkin disease in an adolescent.