pathology

1. Squamous cell carcinoma
DR.SUNDARESAN
PATHOLOGY
LOYOLA COLLEGE

2. Squamous cell carcinoma
•Commonest tumour in men.
•Related to smoking.
•Site: central lung tumour- major from scar.
Macroscopic appearance: Greyish white tumour infiltrating
the bronchial wall into lung parenchyma.
Cut surface: chalky red areas.
Cavity at the centre of the tumour mass due to
coughing out necrotic tissue.

3. Microscopic appearance:
•Well differentiated squamous cell carcinoma composed
of polygonal cells with mitosis and pleomorphism.
•Cytoplasm is eosinophilic ( keratinized) with pyknotic
nuclei.
•Keratin pearl formation- Nests of bright eosinophilic
aggregates of keratin arranged in onion skin pattern.
•Intercellular bridges- These are fine strands of cytoplasm
joining the adjacent tumour cells.

4. Undifferntiated and poorly
differentiated tumours:
•Large cells with abundant
cytoplasm.
•No intercellular bridge
•No keratin pearls.

5. ADENOCARCINOMA:
•Common in women and non smokers.
•Site: arise from the terminal bronchioles or
alveoli walls- peripheral origin.
•Behaviour: small and slow growing than
squamous cell carcinoma.

6. HISTOLOGICAL CLASSIFICATION OF ADENOCARCINOMA:
•Papillary type
•Solid type
•Acinar type
Morphology:
Macroscopic - Bronchial derived discrete tumour at
the periphery of the lung.
Microscopic- Tumour cells are cuboidal or columnar.
•Arranged in acinar , papillary or solid pattern.
•Mucin production is seen except in poorly
differentiated types.

7. BRONCHO ALVEOLAR CARCINOMA
•It is a distinct histological pattern of
Adenocarcinoma
•Origin- broncho alveolar region.
•Accounts for 1 to 9% of lung carcinoma.
•5 year survival rate is 25%

8. Macroscopic Appearance:
•Single or multiple nodules in the peripheral portion
of lung.
•Nodules are mucinous , grey white.
Microscopic Appearance:
•Tumour cells are columnar to cuboidal with varying
degree of anaplasia.
•The cells line the alveolar septa, giving alveolar appearance
to the tumor- Broncho alveolar carcinoma.
•Tumour cells produce mucin.

9. SMALL CELL CARCINOMA:
Most aggressive lung tumour.
Accounts for 15 to 20% of lung carcinoma.
Strongly associated with cigarette smoking.
Functional tumours- produce multiple hormones.
Neuro endocrine tumour.

10. Gross appearance:
Fleshy tumours- nodular or infiltrative.
Destroy the wall of bronchus.
Histological types:
•Oat cell carcinoma- Lymphocyte like cells.
•Intermediate cell- Polygonal cells.
•Combined type- in combination with squamous cell
carcinoma.