Ghon focus with caseous necrosis
Primary tuberculosis When an insensitized person is infected with M. Tuberculosis for the first time primary tuberculosis will develop. Primary tuberculosis is characterized by formation of Ghon focus (white inflammation with consolidation) in upper parts of lung followed by a caseous necrosis in center after sensitization. Regional lymph node also increase in size and caseate often. These foci of caseous necrosis are known as granulomas. In best case the infection heals after primary complex formation. Only a scar in place of ghon focus will remain. In some cases after a granuloma encloses the bacteria and keeps it within, a latent lesion develops. The organisms are dormant and the patient feels well until he/she becomes immunocompromised again. In this case secondary TB develops. If the granuloma doesn't manage to keep the bacteria inside progressive primary tuberculosis will develop to secondary TB ( more on this later ) or in worst case result in Miliary disease. Miliary disease is a massive hematogenous dissemination of M. Tuberculosis. Once bacteria get into the circulation system it can involve any organ like the liver, kidney, meninges, and bone marrow. If miliary TB is not treated immediately prognosis for patients is very bad. Progressive Tuberculosis may resemble bacterial pneumonia which makes it hard diagnose it straight alway.
I'm curious why the lung is so black. This type of tissue degeneration is only usually found with very heavy smokers?
My colleague explained it very well! But yes you're right smoking could be one of the main causes for such dark tissue.
Could be smoking or just working in a factory or living in a city. Most of the study preparations are very old from a time before efficient air filters existed.
