RESUMO: Introdução: As pneumonias necrosantes são uma complicação rara da pneumonia lobar, sobretudo na era pós-antibiótica. Recentemente tem-se assistido no nosso hospital ao acréscimo da incidência destas complicações não sendo claro o motivo que lhe está subjacente.Material e Métodos: Estudo retrospectivo dos casos de pneumonias necrosantes em crianças com menos de 13 anos de idade e previamente saudáveis, ocorridos num período de 2 anos num hospital terciário. Carac-terização clínica, imagiológica e microbiológica e da evolução no internamento e após alta.Resultados: Entre as 392 crianças internadas por pneumonia no período do estudo, 15 crianças (3,4â2,4 anos; 9 rapazes) sem doença prévia conhecida apresentavam evidência de necrose pulmonar na TAC pulmonar. Apesar da antibioticoterapia, a febre persistiu 13â7 dias. Dez doentes desenvolveram pneumatocelos e 3 abcessos pulmonares. Doze doentes apresentavam derrames pleurais associados, tendo nove deles necessitado de drenagem torácica. Foi isolado o agente infectante em 3 doentes (2 S. aureus e 1 Enterobacter cloacae).Conclusões: Os resultados encontrados não permitem esclarecer o aumento recente das pneumonias necrosantes. A baixa taxa de isolamento do agente infeccioso implicado poderá estar relacionada com o frequente uso prévio de antibióticos. As imunodeficiências primárias deverão ser sempre pesquisadas nas pneumonias graves mesmo em crianças previamente saudáveis. Apesar da evolução clínica arrastada e da frequente necessidade de toracotomia, o resultado final foi bom na maioria dos doentes.REV PORT PNEUMOL 2002; VIII (1): ABSTRACT: Background: Necrotizing pneumonia used to be rare in the postantibiotic era. Its incidence appears to be rising in our hospital although there is no clear explanation for that.Patients and Methods: Retrospective analysis of the clinical presentation and evolution of necrotizing pneumonia in previously healthy children admitted at our hospital during two years.Results: Among 392 admissions for pneumonia in the study period, 15 patients (3,4â2, 4 years; 9 boys) had evidence of lung necrosis on thoracic computed tomography. Despite appropriate antibiotic therapy, fever persisted for 13â7 days. Ten patients deve loped pneumatoceles and three lung abscesses. Twelve patients had parapneumonic pleural effusions (4 empyemas), nine of whom need closed chest drainage. An agent was isolated from pleural fluid or blood culture in 3 children (2 S. aureus and 1 Enterobacter cloacae); in two further, bacteria were seen on Gram-stained pleural fluid. Two patients had an immunodefficiency state previously unknown (IgA deficiency and hiper-IgE syndrome). Thoracotomy were performed in 9 patients: 2 pleural debridement, 6 decortication, 1 ressection of a giant pneumatocele, 1 abscess drainage and 2 lobectomies. The mean length of hospital stay was 30â11 days and there were no deaths. During the follow-up period (18â9 months) 3 patients required surgery for recurrent infection or fibrothorax. In the remaining, asymptomatic children, 2 have pleural ticknening, 1 a residual pneumatocele and 1 bronchiectasis.Conclusions: The results of this study do not explain the recent increase of the suppurative complications of community acquired-pneumonia in children. The low rate of infectious agent isolation was probably related with frequent previous antibiotic use. Although the final outcome was generally good, the clinical course was very prolonged and surgery was frequently needed. In order to clarify the reason for the increase of this kind of pneumonia complications a prospective multicenter study is warranted.REV PORT PNEUMOL 2002; VIII (1): Palavras-chave: pneumonia adquirida na comunidade, necrose pulmonar, pneumatocelos, abcesso pulmonar, Key-words: community acquired pneumonia, lung necrosis, pneumatoceles, lung abscess