Respi Lab Session (Sem 3)

Lung: Bronchiectasis

• Show a resected upper lobe with with widely dilated bronchi.
• Thickening of the bronchial walls
• Collapse & fibrosis of the pulmonary parenchyma

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Lung: Acute Pneumonia

 

• Microscopic photograph

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Lung: Pulmonary Embolism

• Seen in the pulmonary artery to the left lung on cut section is a large pulmonary thromboembolus
• Such thromboemboli typically originate in the leg veins/pelvic veins of persons who are immobilized

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Squamous Cell Carcinoma of Lung

 

• Microscopic appearance of squamous cell carcinoma with nests of polygonal cells with pink cytoplasm and distinct cell borders.
• The nuclei are hyperchromatic.
• The center shows attempted keratin pearl formation, sign of differentiation.

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Mycobacterium tuberculosis of lung – AFB stain

• This is an acid fast stain of Mycobacterium tuberculosis (MTB).
• Note the red rods – hence the terminology for MTB in histologic sections/smears: acid fast bacilli

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Lung: Emphysema

• Alveolar walls are thin, atrophic & have broken down to form large spaces
• Thick arrow: Collection of pigment laden macrophages seen.

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Bronchogenic carcinoma (Lung cancer)

• There is a large, gray white to dull yellow neoplastic growth arising from the bronchus
• Solid in nature
• with ill defined margins
• There is also deposition of anthracotic pigment in the lung parenchyma elsewhere.

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Lung: Carcinoma

• Specimen of lung shows large, irregular, firm, gray white mass extending from the hilum to pleura
• The black areas are the anthracotic pigments trapped in the tumor.
• Tumors arising in the hilum are commonly squamous cell carcinomas as in this case.

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Ghon focus

 

• Initial infection with Mycobacterium Tuberculosis in an incompetent individual
• Usually occurs in an upper region of the lung producing a sub-pleural lesion called a Ghon focus (RED ARROW)
• YELLOW ARROW: Focal areas of emphysematous change is also seen.

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Miliary Tuberculosis

• Miliary tuberculosis can occur when tuberculous lung lesions erode pulmonary veins/systemic veins.
• This results in dissemination of tubercle bacilli producing myriads of 1-2 mm lesions in susceptible hosts.’
• Miliary spread limited to the lungs can occur following erosion of pulmonary arteries by tuberculous lung lesions.

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Mesothelioma of the pleura

• This is pleural mesothelioma encasing the right lung completely along with the mediastinum.
• There is marked thickening of the pleura due to the tumour.
• And the mediastinum structures are compressed.

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Lung: Metastatic deposits

• Shows extensive, metastatic deposits distributed in a random fashion in the lung parenchyma.
• The site of the deposits vary, and appear grayish white in colour.

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Mesothelioma of pleura

• Mesothelioma is a rare cancer arising from the mesothelial cells.
• These tumors usually arise in the visceral/parietal pleura, peritoneum and pericardium.
• The dense white encircling tumor mass is arising from the visceral pleura.
• These are big bulky tumors that fill the chest cavity.
• The risk factor for mesothelioma is asbestos exposure.

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Lung: Chronic pneumonia

• Inflammatory cells
• Macrophages
• Inflamed alveolar spaces

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Lobar pneumonia

FIGURE 1

• This is a lobar pneumonia in which consolidation of the entire left upper lobe has occured.

FIGURE 2

• A clearer view of the lobar pneumonia demonstrates the distinct difference between the upper lobe and the consolidated lower lobe (ARROW)

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Bronchopneumonia

• ARROWS: The lighter areas that appear to be raised on cut surface from the surrounding lung are the areas of consolidation of the lung.
• The patchy consolidated areas here very closely match the pattern of lung lobules.
• Typical bacterial organisms include:- Staphylococcus aureus, Klebsiella, E.Coli, Pseudomonas.

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Lung: Fibrosing alveolitis

• Dense interstitial sacs
• Scant inflammatory cells
• Dense fibrosis

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Emphysema

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Bronchiectasis