Where is caseous necrosis found in the body?
Nature of caseous necrosis. Caseation (caseum = cheese) is the “solid” necrosis of the exudative initial alveolar lesion and of the lung tissue surrounding the lesion. It results in alveolar destruction, but the elastic fibers of the alveolar walls and their vessels often persist within the caseous lesion.
Does TB cause caseous necrosis?
Causes. Frequently, caseous necrosis is encountered in the foci of tuberculosis infections. It can also be caused by syphilis and certain fungi. A similar appearance can be associated with histoplasmosis, cryptococcosis, and coccidioidomycosis.
What is the difference between primary tuberculosis and secondary tuberculosis?
Primary and secondary TB are also thought to have characteristic radiographic and clinical features: primary TB is said to be characterized by lower-lobe disease, adenopathy, and pleural effusions, and termed atypical, whereas secondary, or reactivation, TB is associated with upper lobe disease and cavitation, termed …
What is the main complication of primary TB?
Clinical manifestations of TB include primary TB, reactivation TB, laryngeal TB, endobronchial TB, lower lung field TB infection, and tuberculoma. Pulmonary complications of TB can include hemoptysis, pneumothorax, bronchiectasis, extensive pulmonary destruction, malignancy, and chronic pulmonary aspergillosis.
Where does liquefactive necrosis occur?
In organs or tissues outside the CNS, liquefactive necrosis is most commonly encountered as part of pyogenic (pus-forming) bacterial infection with suppurative (neutrophil-rich) inflammation (see also Chapter 3) and is observed at the centers of abscesses or other collections of neutrophils.
Where does coagulative necrosis occur?
Coagulative. Coagulative necrosis generally occurs due to an infarct (lack of blood flow from an obstruction causing ischaemia) and can occur in all the cells of the body except the brain. The heart, kidney, adrenal glands or spleen are good examples of coagulative necrosis.
Which necrosis is classically seen in tuberculosis?
The pathophysiological hallmark of tuberculosis is caseous necrosis, which is thought to result from Mycobacterium tuberculosis–mediated macrophage cell death [4–6].
What is Caseating granuloma?
Caseating granuloma means necrosis involving dead cells with no nuclei and debris. Without microscope, the cheese like pattern was seen in the these granulomas . In all reports of the CREMO patients, the granulomas were noncaseating .
Is primary TB latent?
After an initial infection, the bacteria that causes TB often becomes dormant in the body. But if left untreated, it can become active and infectious. After an initial infection, the bacteria that causes TB often becomes dormant in the body. But if left untreated, it can become active and infectious.
Is calcification seen in primary TB?
Miliary tuberculosis is characterized by randomly distributed tiny nodules (1-2 mm), which tend to be smooth and well marginated. Calcification is notably absent; this observation may aid in differentiating tuberculosis from metastatic diseases such as thyroid carcinoma.
What is Ghon focus?
A Ghon focus is a primary lesion usually subpleural, often in the mid to lower zones, caused by Mycobacterium bacilli (tuberculosis) developed in the lung of a nonimmune host (usually a child). It is named for Anton Ghon (1866–1936), an Austrian pathologist.
What is the pathology of post primary tuberculosis?
This differs from descriptions of the preantibiotic era when many investigators had access to thousands of cases. They reported that post primary tuberculosis begins as an exudative reaction: a tuberculous lipid pneumonia of foamy alveolar macrophages that undergoes caseation necrosis and fragmentation to produce cavities.
Which is a microscopic lesion of tuberculosis ( TB )?
The basic microscopic lesion of TB is granulomatous inflammation, in which granulomas show central caseous necrosis (Figure 2-18). In tissues, M. tuberculosis incites a characteristic macrophage response, in which focal zones of macrophages become surrounded by lymphocytes and fibroblasts.
Where do granulomas develop in post primary tuberculosis?
Granulomas do develop in post primary tuberculosis, but only as a late phenomenon that has virtually no role in the development of cavities. As Canettti reported, granulomas do not precede caseation in post primary tuberculosis, but follow it and are typically located at the periphery of the caseum.
How long does it take for primary tuberculosis to spread?
Although it may progress causing meningitis or disseminated tuberculosis, especially in very young or immunosuppressed individuals, primary tuberculosis typically develops and spreads as caseating granulomas to regional lymph nodes and systemically for only a few weeks before regressing as immunity develops.