Ghon focus

About: Ghon focus is a research topic. Over the lifetime, 11 publications have been published within this topic receiving 110 citations.

Is tuberculosis a lymphatic disease with a pulmonary portal

Abstract: Tuberculosis most commonly presents as a pulmonary disease, in which infection, persistence, and induction of transmissible pathology all occur in the lungs. If viewed as a pulmonary disease, enlarged lymph nodes represent reactive adenitis, and extrapulmonary forms of tuberculosis (including lymphatic tuberculosis) are not transmissible, hence representing an evolutionary dead-end for the pathogen. In an alternative theory, Mycobacterium tuberculosis passes asymptomatically through the lungs and rapidly establishes a chronic lymphatic infection. After a period of weeks to decades secondary lung pathology develops, ultimately allowing transmission to occur. Evidence that supports this lymphatic model includes historical descriptions of human tuberculosis from the preantibiotic era, analogy with other mycobacterial infections, observations of tuberculosis in non-human hosts, and experimental models of tuberculosis disease. At a fundamental level, a lymphocentric model proposes that spread of organisms outside the lung parenchyma is essential to induce adaptive immunity, which is crucial for the generation of transmissible pathology. Furthermore, a lymphatic model could explain why the lesion associated with primary infection (Ghon focus) is anatomically separated from the most common site of reactivation disease (the apex). More practically, an alternative perspective that classes tuberculosis as a lymphatic disease might affect strategies for preclinical and clinical assessment of novel diagnostics, drugs, and vaccines.

Radiological patterns of childhood thoracic tuberculosis in a developed country: a single institution’s experience on 217/255 cases

Abstract: The incidence of tuberculosis is increasing in the developed world and children in particular represent a high-risk group for developing the disease. The aim of this review is to analyse the spectrum of radiological signs as reported in the recent literature, in light of our series over a 15-year period, to pinpoint the most common radiological patterns in a developed country and to determine the role played by the different chest imaging techniques in diagnosis improvement. Lung TB was present in 217 out of 255 patients (85 %): 146 patients were under 5 years of age (76 under 2 years) and 71 over 5 years (41 over 10 years). We describe different patterns differentiating adolescents and young adults from infants and children. Adolescents and young adult tuberculosis are apical and cavitary. Thoracic TB in infants and children is characterized by lymph node and parenchymal disease. In 21 cases with lymphadenopathies without lymph-bronchial diffusion (age range 2 months–7 years), CT identified the Ghon focus in 16/21 cases; chest X-ray never identified the Ghon focus. In our series, pleural TB was present in 8 cases out of 146 under 5 years of age, 5 cases out of 76 under 2 years, and 18 cases out of 71 over 5 years. Radiologists should be aware of typical patterns of tuberculosis, to provide an early diagnosis.

Anton Ghon and His Colleagues and Their Studies of the Primary Focus and Complex of Tuberculosis Infection and Their Relevance for the Twenty-First Century.

Abstract: Anton Ghon is well known in the field of childhood tuberculosis, and the tuberculosis primary focus and complex are frequently called the Ghon focus and complex; this is largely the result of the wide publication of the English translation of his monograph "Der primare Lungenherd bei der Tuberkulose der Kinder." Ghon's studies are frequently quoted, but precise details of his monograph are neglected, his results often misquoted, and his later publications virtually unknown. This review highlights aspects of Ghon's anatomical pathology studies in children and adults not necessarily dying of tuberculosis but with signs of tuberculosis infection. Ghon found a single primary tuberculosis focus in approximately 80% of tuberculosis-infected children situated close to the pleura in two-thirds of cases. Cavitation of the focus was common, and lymphatic spread involved lymph nodes in the abdomen and neck in many children. Studies amongst adults and children frequently found the healed primary tuberculosis focus to be completely calcified without histological signs of tuberculosis activity; however, particularly in the presence of pulmonary tuberculosis, histological signs of tuberculosis activity were often found in the lymph nodes of the angulus venosus, despite apparent healing with extensive calcification. Both earlier studies and more recent investigations, with molecular biological tools, unavailable to Ghon and earlier researchers, have confirmed the presence of viable mycobacteria in apparently normal or healed thoracic nodes and also found molecular biological indications of viable mycobacteria in these nodes. As suggested by Ghon, lympho-haematogenous spread of tuberculosis may be more common than is usually appreciated.