The formula proposed by Rich in 1951 explained the formation in a tuberculous lesion in a period that was unknown cellular functions, cytokines and other immunological aspects involved in granuloma formation by tuberculosis; its components are assembled conceptually to explain the pathogenic mechanisms involved in the granulomatous lesion in tuberculosis. In this manuscript, we report an update of Rich's formula based on the new and old concepts about pathogenic mechanisms involved in the granulomatous lesion in tuberculosis. Current knowledge allows us to conclude that the balance between the characteristics of the bacillus and host protective response is necessary to indicate the outcome of pathogenesis, infection or active disease and the necrosis degree of the tuberculosis lesion.

OBJETIVO: Determinar a sensibilidade do sistema de escore proposto pelo Ministério da Saúde do Brasil em 2002 para o diagnóstico de crianças e adolescentes com suspeita de tuberculose. MÉTODOS: Entre 1997 e 2007, 316 crianças e adolescentes (0-14 anos de idade) com diagnóstico de tuberculose pulmonar no Instituto Brasileiro de Investigação da Tuberculose, em Salvador (BA), foram incluídos no presente estudo retrospectivo. Foram revisados os prontuários médicos e as radiografias de tórax dos pacientes, e os escores foram calculados. RESULTADOS: A maioria dos sujeitos (80,4%) tinha história de contato domiciliar com adultos com BAAR positivo nos últimos dois anos. O teste tuberculínico foi negativo em 11 sujeitos (3,5%). Conforme o sistema de escore, 251 (79,4%) muito provavelmente tinham tuberculose (escores > 40), 63 (19,9%) possivelmente tinham tuberculose (escores entre 30 e 35) e 2 (0,7%) pouco provavelmente tinham tuberculose (escores < 25). A sensibilidade desse sistema de escore foi de 99,3%, com um ponto de corte de 30. CONCLUSÕES: Em nossa amostra, a sensibilidade do sistema de escore foi alta para o ponto de corte selecionado. Com um ponto de corte de 40, 20% dos sujeitos não teriam sido tratados. Portanto, escores entre 30 e 35 são críticos para a definição diagnóstica. Uma avaliação clínica judiciosa deve prevalecer para a decisão de tratar esses pacientes. Com um ponto de corte de 30, 30% dos indivíduos com outras patologias seriam tratados para tuberculose. Isto enfatiza a necessidade de melhores métodos diagnósticos para a tuberculose

OBJECTIVE: To determine the sensitivity of the scoring system proposed by the Brazilian National Ministry of Health in 2002 for the diagnosis of tuberculosis in children and adolescents suspected of having the disease. METHODS: This was a retrospective study of 316 children and adolescents (0-14 years of age) diagnosed with pulmonary tuberculosis between 1997 and 2007 at the Brazilian Institute for Tuberculosis Research, located in the city of Salvador, Brazil. After reviewing the medical charts and chest X-rays of the patients, we calculated the tuberculosis scores. RESULTS: The majority of the subjects (80.4%) had a history of close household contact with an AFB-positive adult within the last two years. The tuberculin test was negative in 11 subjects (3.5%). According to the scoring system, 251 (79.4%) were very likely to have tuberculosis (score, > 40), 63 (19.9%) were moderately likely to have tuberculosis (score, 30-35), and 2 (0.7%) were unlikely to have tuberculosis (score, < 25). When a cut-off score of 30 was used, the sensitivity of this scoring system was 99.3%. CONCLUSIONS: In our sample, the sensitivity of this scoring system was high when the selected cut-off score was employed. If a cut-off score of 40 had been used, 20% of the subjects would not have been treated. Therefore, scores between 30 and 35 are critical for diagnostic confirmation. Judicious clinical evaluation should prevail in the decision of treating these patients. When the cut-off score of 30 is used, 30% of individuals with other pathologies will be treated for tuberculosis. This highlights the need for improved diagnostic methods for tuberculosis

The diversity of clinical presentations of primary progressive tuberculosis (TB) and the difficulty in establishing the diagnosis of paucibacillary forms is the subject of painstaking research, as well as a cause of delay in therapy. We report the case of a 10-year-old black child who presented with chest pain and progressive widening of the upper mediastinum. Computerized tomography of the chest revealed multiple calcifications that were not identified with X-rays. Biopsy through mediastinoscopy was compatible with a diagnosis of tuberculosis. Despite exhaustive investigation that included direct examination, culture for mycobacteria and PCR (Polymerase Chain Reaction) of tissue samples, the etiologic agent was not revealed. Tuberculin conversion was observed during the follow-up and resolution period of the lesion, after administration of isoniazid, rifampicin and pyrazinamide. The nodal pseudotumoral form of tuberculosis is rare in immunocompetent children and it may simulate neoplastic disease; therefore, it should be included in the list of differential diagnoses of masses located in the anterosuperior mediastinum.

A linfadenite necrosante histiocítica, ou linfadenite de Kikuchi (LK), é uma forma rara de linfadenite, geralmente de curso clínico auto-limitado. Raros casos de LK associados à infecção pelo vírus da imunodeficiência humana (HIV) foram relatados, sendo sua patogênese atribuída à disfunção imunológica destes pacientes. O objetivo do presente artigo é relatar um caso de associação de LK em um paciente HIV-positivo. A histomorfologia e a imunofenotipagem foram semelhantes aos casos anteriormente descritos na literatura, mas focos de macrófagos ativados positivos para o CD30 foram vistos, o que pode ser devido ao estado imune do paciente. A pesquisa de EBV por hibridização in situ foi negativa no tecido. Embora rara, a ocorrência de LK em pacientes HIV-positivos deve ser lembrada, por causa do potencial erro diagnóstico com linfoma maligno, especialmente na presença de células CD30+.

Histiocytic necrotizing lymphadenitis, or Kikuchi's lymphadenitis (KL), is an unusual form of lymphadenitis, generally with self-limited clinical course. KL has been reported in rare patients infected with the human immunodeficiency virus (HIV). Pathogenesis of the lesion is probably related to an impaired immune function. The purpose of the present article is to report on one case in which KL was diagnosed in an HIV-infected patient. Histomorphology and immunophenotype were similar to previous reports, but a focus of activated CD30+ macrophages was seen, what might be due to the immunological status of the patient. EBV was not detected on the sections using the in situ hybridization technique. Although rare, the occurrence of KL in HIV-infected subjects must be emphasized, because of the potential misdiagnosis of malignancy, especially in the presence of CD30+ cells.

Seis casos de bola pulmonar intracavitária formada por Actinomycetes são descritos. Eles foram observados no Estado da Bahia, Brasil. Todos os pacientes queixavam-se de tosse e hemoptise e o estudo histopatológico mostrou bronquiectasias e pequenas cavidades no tecido pulmonar. Tais lesões eram ocupadas por micro-colônias de Actinomyces, identificados morfologicamente através de propriedades tintoriais e cultura em dois casos (meio de tioglicolato). Nos seis pacientes, a doença estava limitada aos pulmões. Em um paciente grãos foram encontrados, próximo à cavidade colonizada, dentro de micro-abscesso no interior do parênquima. Provavelmente a invasão ocorreu devido à ulceração da mucosa brônquica que estava coberta por tecido de granulação. O autor sugere que à semelhança da nocardiose, o espectro da actinomicose deve ter uma forma invasiva, uma saprofítica, podendo apresentar uma terceira, como colonizador de cavidades pulmonares pré-existentes.

Six cases of a cavitary pulmonary ball formed by Actinomycetes are reported. They were observed in the state of Bahia, Brazil. All patients complained of cough and hemoptysis and the pathological study showed bronchiectasis and small cavities in the lungs. The lesions contained micro-colonies of Actinomyces, identified by morphology, staining properties and culture in two cases (thioglycolate media). In the six patients the disease was limited to the lungs. In one patient grains were found, within micro-abscesses in the surrounding parenchyma. Probably the invasion occurred due to ulceration of bronchial mucosa that was covered by granulation tissue. The author suggests that as in nocardiosis actinomycosys may have an invasive form, a saprophytic one may and colonize pulmonary cavities.