أسئلة المحاضرة الثالثة باثولوجي RESP (قبل التعديل)

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Questions and Answers

What is the typical size of a caseous lesion in pulmonary tuberculosis?

5-7 cm

2-3 cm

3-5 cm

1-2 cm (correct)

What is the fate of tuberculosis when it leads to localized spread?

It can cause TB Pleurisy (correct)

It results in lymphangitis

It can produce miliary tuberculosis

It leads to tuberculous bronchopneumonia

Which characteristic is true regarding the lesions of miliary tuberculosis?

They appear as poorly developed tubercles (correct)

They are typically surrounded by congested tissue

They are large and irregularly shaped

They contain abundant giant cells

Where are tubercles typically located in cases of pulmonary TB?

Near the upper part of the upper lobe Signup and view all the answers

Which of the following describes the appearance of tubercles in tuberculosis?

Multiple scattered small size tubercles Signup and view all the answers

What typically occurs with good immunity regarding apical lesions in tuberculosis?

Development of a fibrous capsule Signup and view all the answers

In which form of tuberculosis is spread through natural passages more rapid and easier?

Secondary tuberculosis Signup and view all the answers

What characterizes the proliferative reaction in secondary tuberculosis as opposed to primary tuberculosis?

Quicker liquefaction and cavitation Signup and view all the answers

Which of the following is NOT a predisposing factor for tuberculosis?

High nutritional status Signup and view all the answers

What is a potential result of localized tuberculous reaction in an organ?

Development of a large mass mistaken for a tumor Signup and view all the answers

What happens to isolated organ tuberculosis when a patient’s immunity is lowered?

It can reactivate from a latent state Signup and view all the answers

What type of organism primarily causes tuberculosis?

Mycobacterium tuberculosis Signup and view all the answers

In which site does primary tuberculosis commonly occur?

Lung Signup and view all the answers

Which method is NOT used for the transmission of tuberculosis?

Transfusion of blood Signup and view all the answers

What percentage of infected persons typically develop significant disease from tuberculosis?

5% Signup and view all the answers

What is a characteristic of Mycobacterium tuberculosis bacilli?

Acid-fast Signup and view all the answers

Which personal factor is associated with a higher risk of developing tuberculosis?

Immune deficiency states Signup and view all the answers

Which component is NOT part of the structure of tuberculosis?

Exotoxins Signup and view all the answers

What is the role of interferon gamma (INFy) in the immune response against bacilli?

It activates native and blood monocytes. Signup and view all the answers

What characteristic features are associated with Langhans giant cells?

Horseshoe-shaped arrangement of multiple nuclei. Signup and view all the answers

Which factor is primarily responsible for increased blood flow to an area of inflammation?

Tumor necrosis factor (TNF-α) Signup and view all the answers

What happens after 2-3 weeks in the reaction of tubercle formation?

Central caseation begins to occur. Signup and view all the answers

Which of the following describes the cellular response surrounding a caseating tubercle?

Epithelioid cells, Langhans giant cells, and fibroblasts surround it. Signup and view all the answers

What structural changes characterize an epithelioid cell?

Large with vesicular nuclei and eosinophilic cytoplasm. Signup and view all the answers

What is the result of fibroblast activity in the context of tubercle formation?

Formation of a protective capsule around the tubercle. Signup and view all the answers

How does the macrophage's response to ingesting bacilli lead to granuloma formation?

By becoming an epithelioid cell and recruiting others. Signup and view all the answers

What characterizes a pyemic abscess in tuberculosis?

Presence of central pus surrounded by acute inflammatory cells Signup and view all the answers

Which of the following sites is NOT commonly affected by miliary tuberculosis?

Liver Signup and view all the answers

What is the fate of tuberculosis infection in the case of a progressive lesion?

Pulmonary fibrosis and right-sided heart failure Signup and view all the answers

How does miliary tuberculosis spread?

Via blood to different organs Signup and view all the answers

What is the central feature in the pathological examination of a tuberculous granuloma?

Central area of caseation surrounded by granulomatous tissue Signup and view all the answers

What is a significant consequence of local tissue destruction from tuberculosis?

Pneumothorax and pyopneumothorax Signup and view all the answers

Which statement about tuberculosis is true?

Excessive tissue destruction is a result of hypersensitivity reactions. Signup and view all the answers

Which complication is associated with pulmonary tuberculosis?

Reactive systemic amyloidosis Signup and view all the answers

What is the fate of tuberculosis infection if it leads to miliary tuberculosis?

Development of tuberculous bronchopneumonia Signup and view all the answers

Which feature distinguishes tubercles in miliary tuberculosis from other types?

Small size and independence from congestion Signup and view all the answers

What characterizes the lymphangitis associated with tuberculosis?

Inflammation of lymphatic vessels Signup and view all the answers

Which type of lesion is classically found in primary pulmonary tuberculosis?

Caseous lesions with central necrosis Signup and view all the answers

What is a common consequence of tuberculous lymphadenitis?

Formation of abscesses in lymph nodes Signup and view all the answers

What is the nature of caseating lesions in tuberculosis when they reach a larger size?

They are mistaken for a malignant tumor. Signup and view all the answers

What distinguishes the spread of secondary tuberculosis from that of primary tuberculosis?

Secondary tuberculosis does not lead to lymph node enlargement. Signup and view all the answers

Which characteristic is true for the tissue reaction in primary tuberculosis?

It involves a slow, firm, well-formed proliferative reaction. Signup and view all the answers

Which of the following best describes the type of organisms that cause tuberculosis?

Aerobic and non-motile Signup and view all the answers

In cases of latent tuberculosis, what occurs following a decrease in the host’s immunity?

The latent infection can reactivate and lead to active disease. Signup and view all the answers

What is the primary means through which tuberculosis infection is generally acquired?

Inhalation of infectious particles Signup and view all the answers

Which of the following statements correctly describes the nature of blood spread in tuberculosis?

Blood spread in primary tuberculosis is rapid and can be fatal. Signup and view all the answers

Which personal factor is specifically associated with a higher risk of tuberculosis infection?

Malnutrition Signup and view all the answers

In the context of tuberculosis, the term 'granuloma' primarily refers to which of the following?

A collection of macrophages and lymphocytes Signup and view all the answers

What role do macrophages play in the initial response to tuberculosis infection?

They present antigens to initiate a helper T cell response. Signup and view all the answers

Which environmental factor is associated with an increased risk of contracting tuberculosis?

Environmental pollution Signup and view all the answers

Which type of tuberculosis is caused by ingestion rather than inhalation?

Bovine type tuberculosis Signup and view all the answers

What percentage of individuals infected with tuberculosis are expected to develop significant disease?

5% Signup and view all the answers

What characterizes the site of infection in miliary tuberculosis?

Multiple small lesions of uniform size, separated by normal tissue Signup and view all the answers

Which of the following best describes the feature of a pyemic abscess?

Multiple small rounded acute abscesses with hemorrhage Signup and view all the answers

What occurs in cases of progressive lesions in tuberculosis?

Formation of extensive necrotic tissue Signup and view all the answers

Which statement accurately describes the fate of tuberculosis when accompanied by significant caseation?

It leads to excessive tissue destruction and may cause cavitations Signup and view all the answers

In the context of tuberculous lesions, what does the term 'Assmann focus' refer to?

An initial small caseating tuberculous granuloma in the lung apices Signup and view all the answers

What pathological change is commonly seen in advanced pulmonary tuberculosis?

Cavitations and loss of lung architecture Signup and view all the answers

What complication may arise if an apical tuberculous lesion connects to the pleura?

Development of pneumothorax Signup and view all the answers

Which of the following correctly describes the lesions seen in cases of miliary TB?

Multiple small lesions, uniform in size, distributed throughout organs Signup and view all the answers

What is the primary function of interferon gamma (INFy) in the immune response against bacilli?

Activating helper T lymphocytes Signup and view all the answers

Which type of cell is formed by the fusion of multiple epithelioid cells in tuberculosis?

Langhans giant cells Signup and view all the answers

What indicates the onset of central caseation in a tubercle?

Timing of 2-3 weeks after infection Signup and view all the answers

What cellular component is primarily responsible for encircling the tubercle, leading to fibrosis?

Fibroblasts Signup and view all the answers

Which type of immune cell is primarily attracted to the area of infection by tumor necrotizing factor (TNF-α)?

Blood monocytes Signup and view all the answers

What is the appearance of caseating material in a tubercle typically described as?

Eosinophilic and structureless Signup and view all the answers

What occurs to macrophages once they engulf the lipid portion of bacilli?

They transform into epithelioid cells Signup and view all the answers

What is a classic characteristic of Langhans giant cells in tuberculosis?

Eosinophilic cytoplasm Signup and view all the answers

Study Notes

Tuberculosis

Tuberculosis (TB) is a chronic, infective granuloma primarily affecting the lungs, but potentially affecting other body systems.
Environmental factors like low socioeconomic status, poor hygiene, contact with TB patients, overcrowding, and pollution increase susceptibility.
Personal factors such as race (more prevalent in African Americans), malnutrition, debilitating illnesses, and immune deficiency increase the risk.
TB bacilli are aerobic, acid-fast, non-motile, do not produce exotoxins, and are carried by macrophages.
TB bacilli contain carbohydrates, lipids, and proteins, like tuberculoprotein (PPD).
Two main types of TB exist: human, caused by inhalation, and bovine, caused by ingestion.

Tuberculosis Pathogenesis

Primary Pulmonary Tuberculosis (0-3 weeks):
- Mycobacteria proliferate unchecked.
- Macrophages engulf mycobacteria but can't kill them.
- Macrophage activation and resultant granuloma formation occurs.
- This can lead to the development of focal areas of necrosis, known as caseous necrosis.
- The ensuing inflammation creates a tubercle.
Tubercle Formation:
- Formation of Epithelioid cell granulomas(cells with distinct cell borders).
- Formation of giant cells (e.g. langhans cell).
- Proliferation of fibroblasts (collagen production).
Primary Pulmonary Tuberculosis ( > 3 weeks):
- Inflammation continues and macrophage activation leads to excessive granuloma formation.
- IL-12 and IFN-y stimulate Th1 and T cells.
- TNF-alpha is responsible for blood flow to the affected area.
- Monocytes are recruited
- Formation of a caseous granuloma
Types of Tuberculous Reactions:
- Type IV Hypersensitivity: Inflammatory reaction in response to prior exposure.
- No prior exposure: inflammatory reaction in response to initial encounter.

Primary Tuberculosis (Childhood Type)

Incidence: Occurs in younger, non-immunized individuals; exogenous source of infection.
Methods of Infection: inhalation, ingestion, direct contact. Methods of Infection:Inhalation, Ingestion, Direct contact
Site of Primary Complex: Lungs, Tonsils, Skin, Intestine, Nose (less common).
Proliferative Reaction(Tubercle formation): bacilli are taken in by macrophages, organism multiply in macrophages.
Helper T cells secrete Interferon Gamma (IFN-γ).
Cellular reaction: engulfment of lipid part of bacilli and macrophage to epithelioid cell transformation.
Cell fusion to create Langhans giant cells.
Tubercle formation: fibroblast encircles the tubercle, forming a firm tubercle.
Caseation: After 2-3weeks, central caseation develops in the centre of tubercle.

Microscopic Evaluation of Tuberculosis (N/E and M/E)

N/E (Normal Examination): Tubercle is visible (1-3mm in size), with a central yellow area (caseation) and a grey periphery.
M/E (Microscopic Examination): Caseating material is observed in the centre, surrounded by epithelioid cells, macrophages, and multinucleated giant cells (often Langhans giant cells).

Pulmonary Tuberculosis

Pulmonary TB is a common site of TB infection.
A small caseating lesion (1-2 cm) is found beneath the pleura, typically in the lower part of the upper lobe or upper middle lobe.
TB Lymphangitis: Inflammation of lymphatic vessels.
TB Lymphadenitis: Inflammation of lymph nodes.

Primary Tuberculosis Fate

Possible Outcomes: Good fate (healing) or bad fate (spread).
Local Spread: Can cause pleurisy (inflammation of the pleura).
Lymphatic Spread: Spread to peri- and paratracheal lymph nodes, and the mediastinum
Blood Spread: Dissemination as miliary tuberculosis.
Natural Spread: development of tuberculous bronchopneumonia and pneumonia.

Miliary Tuberculosis

Lesions appear as multiple, small, uniform tubercles (3mm) scattered throughout the tissues, separated from each other, not surrounded by congestion.
Microscopic examination shows tubercles related to blood vessels, with poorly developed structures, central necrosis, and absence of giant cells.

Pyemic Abscess

Caused by pyemia (septic blood flow).
Formation of many small, acute abscesses in tissues, especially blood vessel areas.
Areas are rounded, with hyperemic zones surrounding the abscesses.

Secondary Pulmonary Tuberculosis

Acquired from reactivation of a healed primary complex or exogenously.
Age of Onset: Adults.
Site of involvement: Kidneys, suprarenal glands, fallopian tubes, epididymis, brain, meninges, bones, and joints.
Extensive caseation due to hypersensitivity reaction.

Tuberculoma

Localized collection of caseating tuberculous reaction surrounded by fibrous tissue.
May reach large size, potentially mistaken for a tumor.
Can affect any organ, including the lungs, kidneys, and brain.

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