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| - Highly associated with smoking
- Most common in indian sub-continent
- Most common among smokers
- Most common in male
| - Not associated with smoking
- Most common in world
- Most common among non-smokers
- Most common in female
| Highly associated with smoking | |
Etiopathogenesis (Genetic factors) | - Deletion in 3p, 9p and 17p chromosomes → Loss of tumor supperssor loci
- Mutation of TP53 gene → Overexpression of p53 protein
- Loss of expression of the Retinoblastoma (RB) tumor suppressor gene
- Inactivation of cyclin-dependent kinase inhibitor gene (CDKN2A) → Loss of its protein product (p16)
- Loss of Fibroblast growth factor receptor gene (FGFR1)
| - Loss of function Mutation in EGFR, ALK, ROS, MET and RET gene
- Mutation in the KRAS gene
| - Mutation in TP53 and RB gene
- Deletion of 3p chromosome
- Amplification of genes of MYC family
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Prognosis and Response to treatment | | | - Worst prognosis due to high metastasis
- But also highly responsive to Chemotherapy and Radiotherapy
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| | | - Highly metastatic
- Brain → Fist site for metastasis
- Adrenal → Second site for metastasis
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| Gross graph TD
1["Squamous metaplasia/ Dysplasia"]
2["Carcinoma in situ<br>- Atypical cells may be identified in cytologic smears of sputum or in bronchial lavage fluids or brushings. <br>- Lesion is asymptomatic and undetectable on radiographs. <br>- Last for several years."]
3["Invasive squamous cell carcinoma"]
4["Grows exophytically into the bronchial lumen."]
5["Produces intraluminal mass."]
6["Obstruction of bronchus with further enlargement."]
7["Distal atelectasis and infection."]
8["Penetrate the wall of the bronchus."]
9["Infiltrate along the peribronchial tissue into the adjacent carina or mediastinum."]
10["Tumors grows along a broad front to produce a cauliflower-like parenchymal mass <br>that pushes lung substances ahead of it."]
1 --> 2
2 --> 3
3 --> 4
4 --> 5
5 --> 6
6 --> 7
3 --> 8
8 --> 9
3 --> 10 - Neoplastic tissue is gray-white and firm to hard.
- In bulky tumors, focal areas of hemorrhage or necrosis produces red or yellow-white mottling and softening.
- Sometimes, these necrotic foci cavitate.
Microscropic Poorly differentiated - Keratin pearl and keratinization are focal and not well developed.
- High mitotic activity.
Moderately differentiated forms - Individual cell keratinization, intercellular bridges and keratin pearls are easily seen but not as extensive as well differentiated forms.
Well differentiated forms - Presence of keratinization and intercellular bridges.
- Keratin pears are markedly eosinophilic.
| Gross Atypical adenomatous hyperplasia - It is a small lesion (<=5 mm) characterized by dysplastic pneumocytes lining alveolar walls that are mildly fibrotic.
- It can be single or multiple and can be in the lung adjacent to invasive tumor or away from it.
Adenocarcinoma in situ - It was formly called Bronchioalveolar carcinoma.
- It is a lesion less than 3 cm.
- It is composed entirely of dysplastic cells growing along preexisting alveolar septae.
- The cells have more dysplasia than atypical adenomatous hyperplasia.
- It may or may not have intracellular mucin.
Adenocarcinoma - It is an invasive malignant epithelial tumor with glandular differentiation or mucin production by the tumor cells.
- It grow in various patterns, including acinar, lepidic, papillary, micropapillary, and solid with mucin formation.
● Microscopic: - They vary histologically into following forms.
- Well-differentiated tumors with obvious glandular elements.
- Papillary lesions resembling other papillary carcinomas.
- Solid masses with only occasional mucin-producing glands and cells.
- Lepidic pattern of growth (Tumor cells crawl along normal-appearing alveolar septae.
| - Cells features
- relatively small (generally smaller than 3 times the diameter of a small resting lymphocytes)
- scant cytoplasm
- ill-defined cell borders
- finely granular nuclear chromatin (Salt and pepper pattern), and
- absent or inconspicuous nucleoli.
- Round, oval, or spindle-shaped
- Prominent nuclear molding.
- High mitotic count.
- Cells grow in clusters that exihit neither glandular nor squamous organization.
- Necrosis is common and often extensive.
- Azzopardi effect: Basophilic staining of vascular walls due to encrustation by DNA from necrotic tumor cells.
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| | | - Chromogranin
- Synaptophysin
- CD57
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