The reversed halo sign is seen in approximately 10% of patients with paracoccidioidomycosis. In these patients, this sign reflects the presence of a central area of predominantly interstitial inflammation surrounded by predominantly air-space infiltration.

The high-resolution CT findings of patients with pulmonary PCM who have not yet been treated consist of ground-glass attenuation areas associated with small centrilobular nodules, cavitated nodules, large nodules, parenchymal bands, and areas of cicatricial emphysema. These abnormalities are usually distributed in the posterior and peripheral regions of the lungs, with discrete predominance in the middle lung zones.

Physical examination demonstrated petechiae, leg oedema and mild dyspnoea. Chest radiograph showed minimal bilateral hazy increased opacification, mainly on the right side, and small bilateral pleural effusions. High-resolution CT demonstrated extensive bilateral ground-glass opacities most severe in the middle and lower lung zones. Also noted were a few slightly thickened interlobular septa, a few poorly defined small nodules, bronchial wall thickening and small bilateral pleural effusions. Blood tests revealed high leukocyte and low platelet counts. Renal function was normal. Serological test (ELISA) for hantavirus using SNV (Sin Nombre virus) antigen was positive. The patient received supportive treatment, gradually improved, and was discharged 10 days after hospital admission. His symptoms completely resolved and follow-up radiographs returned to normal.

We report a case of a fetus with an ultrasonography diagnosis of a neuroblastoma during a routine third trimester fetal scan, which presented as a hyperechogenic nodule located above the right kidney. No other abnormalities were found in the ultrasonography scan; however, the follow-up ultrasonography during the 36th week of gestation revealed that the lesion had doubled in size. At the same time, magnetic resonance imaging demonstrated a round mass in the topography of the right adrenal gland with a low signal on T1-weighted images and slightly high signal on T2-weighted images, causing a slight inferior displacement of the kidney. The liver had enlarged and had heterogeneous signal intensity, predominantly hypointense on T2-weighted sequences. Based on these findings, a diagnosis of congenital adrenal neuroblastoma with liver metastases was suggested. A newborn male was delivered by cesarean section 2 weeks later. The physical examination of the neonate revealed abdominal distention and hepatomegaly. The infant had a clinical follow-up in which no surgical or medical intervention was required. At 5 months of age, the infant was asymptomatic with a normal physical examination.

A 6-year-old female patient who underwent bone marrow transplantation because of Fanconi anaemia presented with fever, dyspnoea and cough 17 days after the procedure. The physical examination revealed diffuse crackles. Chest radiographs demonstrated diffuse alveolar opacities in both lungs. High-resolution CT showed a diffuse and bilateral lung lesion characterized by multifocal areas of air-space consolidation associated with ground-glass attenuation and small centrilobular nodules. The culture of the material obtained with bronchoalveolar lavage only demonstrated growth of Stenotrophomonas maltophilia. The patient rapidly presented respiratory insufficiency and death in the same day.

RESUMO -O acometimento cerebral pela histoplasmose é raro, ocorrendo mais comumente sob a form a de doença disseminada. Raramente, a doença pode ocorrer sob a forma de histoplasmomas, que simulam t u m o res do sistema nervoso central. Mais raro ainda é a ocorrência de histoplasmomas em pacientes imunocompetentes como única manifestação desta infecção. Neste relato é apresentado um paciente masculino de 13 anos com cefaléia, vômitos, redução da acuidade visual e auditiva à esquerda e hemipare s i a à direita. A ressonância magnética mostrou lesão expansiva com impregnação anelar de contraste, localizada na região talâmica, hipotalâmica e quiasmática à esquerda. Foi realizada biópsia estereotáxica e a avaliação histológica do material definiu o diagnóstico de histoplamose. Iniciou-se tratamento com fluconazol, com melhora clínica importante após 6 meses do início do tratamento.PALAVRAS-CHAVE: histoplasmose, sistema nervoso central, ressonância magnética. Histoplasmoma as isolated central nervous system lesion in an immunocompetent patientABSTRACT -The cerebral lesions are uncommon in patients with histoplasmosis, occurring more fre q u e n t l y in the disseminated form of the disease. Rare l y, the disease may present as a histoplasmoma, simulating a neoplastic lesion. The histoplasmoma as the only manifestation of this infection in immunocompetent patients is even rare r. This case re p o rt describes a 13 year-old male patient with headache, vomit, low visual acuity and auditive deficit on the left, and paresis on the right. The magnetic resonance image showed an expansible lesion in the thalamic, hypothalamic, and chiasmatic regions, which showed ring enhancement. The stereotactic biopsy was perf o rmed and the histological diagnosis of histoplasmosis was defined. The t reatment was initiated with fluconazole. The patient showed important clinical improvement after 6 months.KEY WORDS: histoplasmosis, central nervous system, magnetic resonance A histoplasmose é doença causada pelo fungo Histoplasma capsulatum, que é endêmico em det e rminadas regiões do mundo, dentre elas o Brasil. Grandes inóculos do fungo, dispersos no ar, favorecem a infecção, que pode ser dividida em: 1. doença progressiva grave, em geral disseminada, acometendo indivíduos com compro m e t i m e n t o da imunidade; 2. doença localizada, em geral autolimitada, tendendo a ocorrer em surtos e acometendo indivíduos imunocompetentes 1 , 2 . O acometimento do sistema nervoso central (SNC) é incomum, sendo mais freqüente em pacientes imunodeprimidos, sob a forma de doença disseminada. A ocorrência da infecção cerebral sob a forma tumoral (histoplasmoma) é rara, e em geral re p resenta manifestação da doença disseminada. Nestes casos, o diagnóstico diferencial com neoplasias cerebrais através de dados clínicos e de imagem muitas vezes é difícil, tornando a biópsia da lesão inevitável para que se obtenha a definição diagnóstica 1,3,4 . Relatamos um caso de histoplasmose com aco-

A 17-year-old boy presented with somnolence and mental confusion. Physical examination demonstrated motor disturbances. Laboratory investigation showed elevated levels of alpha-fetoprotein in serum and cerebrospinal fluid. The CT scan revealed a heterogeneous mass at the pineal region. At the MRI, this lesion was hypointense on T1 and hyperintense on T2-weighted images, enhancing after contrast administration. The patient underwent a surgical biopsy, which defined the diagnosis of yolk sac tumor. We emphasize the correlation of neuroimaging and pathological findings of this rare pineal region tumor.

-Objective: To present the imaging findings of a patient with diffuse brain injury secondary to intoxication with oral hypoglycemics. Case re p o rt: A nine years-old boy presented with generalized tonic-clonic convulsions and decreased consciousness. Laboratory investigation demonstrated blood glucose level of 21 mg/dL. The magnetic resonance imaging showed cortical and subcortical temporo -p a r i e t o -o c c i pital areas of high signal on T2 and low signal on T1, with high signal on the diffusion-weighted images and low signal on apparent diffusion coefficient maps. Conclusion: C o rtical and subcortical temporal, parietal and occipital ischemic lesions may be seen in patients with intoxication by oral hypoglycemics.KEY WORDS: magnetic resonance imaging, diffusion weighted imaging, hypoglycemia.Intoxicação com hipoglicemiante oral como causa de lesão cerebral difusa: relato de caso RESUMO -Objetivo: Apresentar os achados de imagem em um caso de lesão cerebral difusa secundária a intoxicação por hipoglicemiante oral. Relato do caso: Menino de nove anos de idade apresentando crises convulsivas tônico-clônicas e rebaixamento do nível de consciência. Exames laboratoriais revelaram glicose sérica de 21 mg/dL. O exame de ressonância magnética revelou lesões corticais e subcorticais têmporo -parieto-occipitais, com alto sinal em T2 e baixo em T1, apresentando hipersinal nas imagens ponderadas em difusão e hipossinal nos mapas de coeficiente aparente de difusão. Conclusão: Lesões isquêmicas corticais e subcorticais nos lobos temporais, parietais e occipitais podem ser identificadas em pacientes com intoxicação por hipoglicemiantes orais. PALAVRAS-CHAVE: ressonância magnética, imagens ponderadas em difusão, hipoglicemia. D i ffuse brain injury are caused by several disorders, such as hypoglycemia. In addition, diff e rent conditions may cause hypoglycemia. In neonates, the most common causes are maladaptive metabolic adjustments in the transition intrauterine to extra uterine life, intrauterine under nutrition, and primary enzymatic or metabolic endocrine abnormalities. Considering another ages, exogenous intoxication and hypoxic-ischemic disorders are the causes of hypoglycemia most frequently demonstrated 1 , 2 . The histopathological findings seen in patients with transient hypoglycemia and diffuse brain injury have been documented. However, there are only a few studies s t ressing the imaging findings in these patients 1 -4 . Barkovich et al. 2 , reviewed the imaging findings of five patients with transient neonatal hypoglycemia. The most common feature was diffuse cortical and s u b c o rtical white matter damage, with the parietal and occipital lobes being affected more severe l y. Globus pallidus injury was seen only in one patient, who had the most severe cortical injury. The diff usion-weighted image (DWI) is a neuroimaging technique that evaluates the water movement, detecting the tissue injury as in acute cerebral damages. Singhal et al.5 demonstrated the DWI features in t h ree patients ...