Felipe Mussi von Ranke

Infectious Diseases Causing Diffuse Alveolar Hemorrhage in Immunocompetent Patients: A State-of-the-Art Review

Diffuse alveolar hemorrhage (DAH) represents a syndrome that can complicate many clinical conditions and may be life-threatening, requiring prompt treatment. It is recognized by the signs of acute- or subacute-onset cough, hemoptysis, diffuse radiographic pulmonary infiltrates, anemia, and hypoxemic respiratory distress. DAH is characterized by the accumulation of intra-alveolar red blood cells originating most frequently from the alveolar capillaries. It must be distinguished from localized pulmonary hemorrhage, which is most commonly due to chronic bronchitis, bronchiectasis, tumor, or localized infection. Hemoptysis, the major sign of DAH, may develop suddenly or over a period of days to weeks; this sign may also be initially absent, in which case diagnostic suspicion is established after sequential bronchoalveolar lavage reveals worsening red blood cell counts. The causes of DAH can be divided into infectious and noninfectious, the latter of which may affect immunocompetent or immunodeficient patients. Pulmonary infections are rarely reported in association with DAH, but they should be considered in the diagnostic workup because of the obvious therapeutic implications. In immunocompromised patients, the main infectious diseases that cause DAH are cytomegalovirus, adenovirus, invasive aspergillosis, Mycoplasma, Legionella, and Strongyloides. In immunocompetent patients, the infectious diseases that most frequently cause DAH are influenza A (H1N1), dengue, leptospirosis, malaria, and Staphylococcus aureus infection. Based on a search of the PubMed and Scopus databases, we review the infectious diseases that may cause DAH in immunocompetent patients.

Recurrent respiratory papillomatosis: A state-of-the-art review

Recurrent respiratory papillomatosis (RRP) is a benign disease of the upper aero-digestive tract caused by human papillomavirus (HPV) infection, which affects children and young adults. The aim of this review is to describe the main etiological, epidemiological, clinical, diagnostic, and treatment aspects of RRP. Most infections in children occur at birth, during passage through the birth canals of contaminated mothers. In adults, HPV is transmitted sexually. Papillomas usually appear as exophytic nodules, primarily in the larynx, but occasionally involving the nasopharynx, tracheobronchial tree, and pulmonary parenchyma. The disease course is unpredictable, ranging from spontaneous remission to aggressive persistent or recurrent disease. Although it occurs rarely, RRP has the potential for malignant transformation to squamous cell carcinoma. Clinically, RRP usually presents with nonspecific symptoms of airway involvement, including chronic cough, hoarseness, wheezing, voice change, stridor, and chronic dyspnea. Helical computed tomography (CT) is highly accurate for the identification and characterization of focal or diffuse airway narrowing caused by nodular vegetant lesions. The typical CT pattern of lung papillomatosis consists of numerous multilobulated nodular lesions of various sizes, frequently cavitated, scattered throughout the lungs. Bronchoscopy is the most reliable method for the diagnosis of RRP; it enables direct visualization of lesions in the central airways and collection of biopsy samples for histopathological diagnosis, and is also useful for therapeutic planning. The definitive diagnosis of RRP is based on histopathological analysis. Currently, no definitive curative treatment for RRP is available; despite the availability of adjunctive treatments, surgery remains the mainstay of treatment.

Pulmonary Involvement in Niemann–Pick Disease: A State-of-the-Art Review

Niemann–Pick disease is a rare autosomal recessive lysosomal storage disease with three subtypes. Types A and B result from a deficiency of acid sphingomyelinase activity, associated with the accumulation of lipid-laden macrophages (so-called Niemann–Pick cells) in various tissues, especially the liver and spleen. Type A is a fatal neurodegenerative disorder of infancy. Type B Niemann–Pick disease is a less severe form with milder neurological involvement, characterized by hepatosplenomegaly, hyperlipidemia, and pulmonary involvement; most patients live into adulthood. Type C Niemann–Pick disease is a complex lipid storage disorder caused by defects in cholesterol trafficking, resulting in a clinical presentation dominated by neurological involvement. Pulmonary involvement occurs in all three types of Niemann–Pick disease, but most frequently in type B. Respiratory manifestations range from a lack of symptoms to respiratory failure. Progression of respiratory disease is slow, but inexorable, due to the accumulation of Niemann–Pick cells in the alveolar septa, bronchial walls, and pleura, potentially leading to a progressively worsening restrictive pattern on pulmonary function testing. Bronchoalveolar lavage has important diagnostic value because it shows the presence of characteristic Niemann–Pick cells. Radiographic findings consist of a reticular or reticulonodular pattern and, eventually, honeycombing, involving mainly the lower lung zones. The most common changes identified by high-resolution computed tomography are ground-glass opacities, mild smooth interlobular septal thickening, and intralobular lines. The aim of this review is to describe the main clinical, imaging, and pathological aspects of Niemann–Pick disease, with a focus on pulmonary involvement.

Imaging of tuberous sclerosis complex: a pictorial review

Tuberous sclerosis complex (TSC) is a genetically determined hamartomatous neurocutaneous disease with high phenotypic variability. TSC is characterized by widespread hamartomas and benign, or rarely malignant, neoplasms distributed in several organs throughout the body, especially in the brain, skin, retina, kidney, heart, and lung. Common manifestations include cortical tubers, subependymal nodules, white matter abnormalities, retinal abnormalities, cardiac rhabdomyoma, lymphangioleiomyomatosis, renal angiomyolipoma, and skin lesions. The wide range of organs affected by the disease implies that TSC1 and TSC2 genes play important roles in the regulation of cell proliferation and differentiation. Although recent advances in treatment have improved morbidity, the prognosis remains quite poor and nearly 40% of patients die by the age of 35 years. Imaging is important in the evaluation of TSC because of its role not only in presumptive diagnosis, but also in defining the full extent of involvement. This information allows a better understanding of the behavioural phenotype, as related to lesion location. Imaging also contributes to treatment planning. This pictorial review describes common and uncommon imaging manifestations of TSC.

Congenital lobar emphysema

http://dx.doi.org/10.1590/0100-3984.2016.0144 Kelly Tung1, Ba D. Nguyen1 1. Department of Radiology, Mayo Clinic, Arizona, Scottsdale, AZ, USA. Mailing address: Ba D. Nguyen, MD. Department of Radiology, Mayo Clinic, Arizona. 13400 East Shea Blvd., Scottsdale, AZ, 85259. E-mail: nguyen.ba@mayo.edu. malignancy. Isolated EMPD, without a coexisting internal primary lesion, is usually an indolent, slow-growing cancer that rarely metastasizes. Rare invasive EMPD has a propensity to metastasize to inguinal nodal basins. EMPD involving the external genitalia has a strong association with gastrointestinal and genitourinary adenocarcinomas. A small subset of invasive EMPD cases show signet-ring cell morphology with extracellular mucin. Immunohistochemical analysis establishes the distinction between signet-ring cells intrinsic to EMPD and those originating from coexisting visceral neoplasms. Poor prognostic factors include dermal invasion, nodular skin lesions, lymph node involvement, and distant metastasis. Given the multiple presentations of EMPD and their varying prognoses, there is a need to identify distant metastases and the primary visceral tumor: that effort is facilitated by functional F-FDG PET/CT imaging.

High-resolution computed tomography findings in hantavirus pulmonary syndrome

1. Assistant Professor of Radiology at the Universidade Federal Fluminense (UFF), Niterói, RJ, Radiologist and Medical Coordinator at Dimagem – Diagnóstico por Imagem, Nova Iguaçu, RJ, Brazil. E-mail: feliperanke@yahoo.com.br. Despite the high incidence and lethality of hantavirus pulmonary syndrome (HPS), there is limited information in the literature about the high-resolution computed tomography (HRCT) features of the disease. There have been only a few case reports describing the tomographic findings of HPS(1–3), and there have been none presenting HRCT findings in a series of patients. In the previous issue of Radiologia Brasileira, Barbosa et al.(4) published an important study on the HRCT findings in eight patients with confirmed HPS. HPS is considered an emerging zoonotic disease. Humans are infected by hantaviruses after inhalation of aerosolized virus particles from rodent urine, saliva, or dried excreta(5). Hantaviruses are commonly categorized as Old World or New World, depending on the geographic distribution of their rodent reservoirs, and the illnesses resulting from infection with the Old and New World hantaviruses are designated hemorrhagic fever with renal syndrome and HPS, respectively. Hemorrhagic fever with renal syndrome occurs in Europe and Asia, whereas HPS occurs in the Americas(6). In the Americas, HPS is the most serious manifestation of hantavirus infection, being characterized by severe pulmonary involvement that leads to respiratory failure and cardiogenic shock, with a high case-fatality rate(6,7). The case-fatality rate of HPS in Brazil is quite high, ranging from 33% to 100%, depending on the region(7). Most cases occur in the southern and southeastern regions of the country, and the disease primarily affects young adult males during the course of occupational activities, tourism to rural areas, or flooding. The first cases of HPS diagnosed in Brazil occurred in 1993 in the state of São Paulo(7). Since then, approximately 1,500 cases of HPS have been reported in the country(7,8). The pathogenesis of HPS is believed to be related to the immune response to the virus, which is responsible for endothelial damage and increased capillary permeability, leading to pulmonary edema. Although hantavirus antigen is present in microvascular endothelial cells, the disturbance is basically functional and most patients do not develop alveolar damage(5). The most commonly reported signs and symptoms are acute fever, chills, generalized myalgia, asthenia, headache, and nausea. During the prodromal phase, dyspnea, tachypnea and dry cough are common(9,10). Respiratory manifestations evolve to the cardiopulmonary phase, thus worsening the respiratory distress, including progressive dyspnea. Within a few hours, the patient develops respiratory failure and a dry cough, which can become productive with expectoration of bloody mucus. Along with respiratory distress and failure, the patient will become hypotensive and tachycardic, and cardiovascular chock soon ensues(7). The reported prevalence of hemorrhagic manifestations among patients with HPS in Brazil ranges from 4% to 37.5%(7). When there is clinical suspicion and the epidemiologic history is consistent with the disease, the etiologic diagnosis is made on the basis of serologic tests and detection of the viral genome by reverse transcriptionpolymerase chain reaction(5). Histopathological examination of the lungs can reveal interstitial and alveolar edema, as well as alveolar hemorrhage and mild interstitial pneumonia, characterized by infiltrates of immunoblasts and mononuclear cells(5). Recent studies in the radiology literature of Brazil have focused on describing the imaging aspects of numerous infectious diseases(11–16). Radiographically, HPS presents as interstitial edema with or without rapid progression to airspace disease in a central or bibasilar distribution(5). On HRCT, the predominant features are bilateral areas of ground-glass opacities and smooth interlobular septal thickening, although the crazy-paving pattern is observed in a minority of cases. Poorly defined small nodules, focal consolidations, peribronchovascular thickening, and pleural effusion can accompany the main findings(5). Such findings are nonspecific, and the differential diagnosis should consider other infectious and noninfectious lung diseases(2). The clinical and radiological differential diagnoses of HPS include dengue and leptospirosis in epidemic areas; other infectious causes of severe respiratory disease, such as influenza and atypical pneumonia; and acute febrile illnesses such as malaria, yellow fever and spotted fever, especially in tropical areas(5,7). In conclusion, the Barbosa et al.(4) study contributes important information on the patterns of HRCT findings in a series of patients with HPS. Knowledge of the main radiological and tomographic patterns of HPS, taken together with the relevant clinical and epidemiological data, provides a fundamental contribution to the differential diagnosis of HPS, as well as to the management of HPS patients with acute febrile illness and severe respiratory distress syndrome.

Postictal MRI features with a unilateral pattern

A 14-year-old female presented with focal seizure and secondary generalized convulsive status epilepticus lasting 2 hours. Electroencephalography revealed diffuse slow waves. Magnetic resonance imaging performed 2 days after onset demonstrated cortical swelling, gyri effacement, and restricted diffusion affecting the right temporal and parietal lobes (Figure). The differential diagnosis of these abnormalities included infarction, ischemia, venous thrombosis, vasculitis, infection, neoplasm, and metabolic encephalopathy. Because imaging findings were resolved completely after 38 days without specific treatment aside from supportive seizure therapy, infarction, venous thrombosis, vasculitis, infection, and neoplasm became less likely. Seizure-induced transient cerebral swelling was the most probable diagnosis.