Lung Tumor Pathology Flashcards
Types of lung tumors
1ry
Benign
Malignant
2ry
By metastasis
90% tumors are carcinoma
Why lung tumors common
Receive entire CO
Main contribution for lung CA
Smoking
2nd common CA in male
How tobacco smoking cause lung CA
Progressive changes in lung epithelium
1) Metaplasia
2) Dysplasia
3) Malignancy
Can non smoker cause Lung CA
Yes
2nd hand/passive smoking
Or
Other factors
Other effects of smoking
1. Increased risk of coronary artery disease : Cigarette smoke contains toxic chemicals, such as carbon
monoxide, that reduce the amount of oxygen carried by the blood. This can lead to the formation
of fatty plaques in the arteries, known as atherosclerosis, which can eventually block blood flow to
the heart and cause a heart attack.
2. Elevated blood pressure: The chemicals in cigarette smoke can cause blood vessels to constrict,
leading to an increase in blood pressure. Prolonged exposure to smoke can result in chronic
hypertension, which is a significant risk factor for heart disease and stroke.
3. Impaired endothelial function: The endothelium is the inner lining of blood vessels, and it plays a
crucial role in maintaining vascular health. Cigarette smoke damages the endothelial cells,
impairing their function and reducing the production of nitric oxide, a compound that helps blood
vessels relax. This endothelial dysfunction contributes to the development of atherosclerosis and
increases the risk of blood clots.
4. Increased risk of blood clots: Smoking increases the likelihood of blood clots forming within the
blood vessels. These clots can partially or completely block blood flow, leading to conditions such
as deep vein thrombosis, pulmonary embolism, or stroke.
5. Cardiac arrhythmias: Cigarette smoke contains chemicals that can disrupt the normal electrical
signaling in the heart, leading to abnormal heart rhythms or arrhythmias. These irregular
heartbeats can have serious consequences and increase the risk of heart failure or sudden cardiac
death.
6. Increased oxidative stress and inflammation: Cigarette smoke triggers oxidative stress in the body,
causing an imbalance between harmful free radicals and the body’s antioxidant defenses. This
oxidative stress, combined with the inflammatory response triggered by smoke exposure, can
damage the heart muscle and promote the development of cardiovascular diseases.
6
Other aetiology for lung CA
- Occupational exposure for carcinogen
Asbestos
Ni,Cr,Cd,As
High dose ionizing radiation (Ur)
Air pollutants
Radioactive gases - Lung fibrosis
- Genetic predisposition
Lung CA related oncogenes
C-MYC, KRAS, EGFR, ALK, C-KIT, C-MET
Inactive tumor suppressor genes of lung CA
P53, RB1, p16
Major histological categories of Lung CA
1 Squamous cell carcinoma
2 Adenocarcinoma
3 Small cell carcinoma
4 Large cell undifferentiated carcinoma
Clinical lung CA types
Small cell carcinoma (SCLC)
• almost always metastatic and with poor prognosis
• High initial response to chemotherapy
– Non-small cell carcinoma (NSCLC)
• Less often metastatic
• Less responsive to chemotherapy
Sub categories of NSCLC
▪Squamous cell carcinoma (SqCC)
▪Adenocarcinoma (AC)
▪Large cell undifferentiated carcinoma (LCUC)
Immunohistochemistry and molecular markers
will assist in this
Morphological types of Lung CA
Central Lung tumors
• squamous carcinomas
• small cell carcinomas
Peripheral lung tumors
•adenocarcinoma
What is cental lung tumors
Tumours arising from the main bronchi close to the hilum of lung
Solid,haemorrhagic and necrotic tumours
• Ulceration of the tumour leads to blood stained
sputum which can contain malignant cell.
•Identified on sputum cytology
Peripheral Lung tumors
Tumours arising from alveolar septal cells or
terminal bronchioles
Morphology of Lung CA ** distal to the tumor**
– Features of bronchial
obstruction
• Partial-emphysema
• Complete -atelectasis
– Accumulation of mucus
– Consolidation of
parenchyma
– abscess formation
Non Small Cell Carcinomas
▪Squamous cell carcinoma (SqCC)
▪Adenocarcinoma (AC)
▪Large cell undifferentiated carcinoma (LCUC)
Squamous Cell Carcinoma (SqCC)
smoking
Cental tumors
• Haemorrhagic and necrotic mass
**By sqamus Metaplasia **
Adenocarcinoma
Smoking
Peripheral tumors
Associates with pulmonary fibrosis
Most common lung CA in non smoking women
Macroscopy Adenocarcinomas
• Commonly a single peripheral
nodule with a central scar
• Could be multiple – mimic
metastatic deposits
• Could be central tumours
• Can contain carbon pigments
• Marked scaring due to
desmoplasia
From where Adenocarcinomas arise
alveoli or
terminal bronchioles.
Different growth patterns of Adenocarcinomas
1 Micropapillary pattern
2 Acinar pattern
3 papillary pattern
Large Cell Undifferentiated Carcinoma
Highly aggressive and destructive lesion with
haemorrhage and necrosis
• Usually central tumours, can be peripheral as well.
HistologyvLarge Cell Undifferentiated Carcinoma
– gross nuclear pleomorphism with numerous
bizarre mitosis.
– No squamous or glandular differentiation
