morphological variants of lung cancer

7/30/2019 Morphological Variants of Lung Cancer

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Morphological variants of Lung Cancer- Squamous cell carcinoma- Adenocarcinoma- Small Lung Cell Carcinoma (SLCC)- Carcinoid airway cancer

Stats- Leading cause of death- Men > women- Trend is increasing in women now- Peak incidence in 50s and 60s

Eitiology

- Tobacco smoke mutations- Proportional to duration, amount &

quality of smoking & deep inhaling.- 90% are smokers and 10% are non

smokers- 20 fold risk if >40cigarettes per day

- >100 fold combined with Asbestos,coal, radon, etc.

Smoke carcinogens.- Initiators Benzo-pyrenes- Promoters Phenol derivatives- Radioactive substances Polonium,

C14, K40- Overall: damage p53 and KRAS etc.

Overall causes:- Smoking*

- Occupational exposure:- Asbestosis, Nickel, chromates, mustardgas, arsenic coal-tar distillation.

- Fibrosis/scaring- TB, Pneumoconiosis, honeycomb lung

Ad.ca.- Radioactive gases

- Radon, Atomic bomb survivors.

Clinical Features:- Weight loss Cytokines.. IL6, IL8, PIF.- Cough Bronchus, obstruction,

necrosis.

- Haemoptysis Invasion, less stroma,necrosis.

ComplicationsLocal:

- Obstruction- Effusion- Pneumonia* lipid, other.- Bronchiectasis- Atelectasis lung collapse- Haemoptysis- COPD (risk)

Systemic: (paraneo symptoms)- Cachexia- Paraneoplastic syndrome- Clubbing- Pulm. Osteoarthropathy.- Bone pain

- CNS dysfunction

Bronchogenic Ca (95%)

Small cell ca. SCC 15-20%(oat cell ca)

Non Small cell NSCC 80%

Squamous cell carcinoma 20-30%

Adeno carcinoma(+Broncho-alveolar)30-40%

Large cell anaplasticcarcinoma (rare)

BronchialCarcinoidTumor (5%)

MiscellaneousTumors

(angio(sarco)ma,fibro(sarco)ma, etc) (


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SCC NSCC- early spread- NO surgery- Responds to

chemo

- Late spread localized- Staging & Surgery - OK- Does not respond to

chemo.

Pathogenesis

Cdewqd

Investigations- Imaging X-Ray, US, MRI, CT, PET- Cytology sputum, Bronchial lavage- Bronchoscopy- Biopsy Needle, excision- Tumor markers.

- Staging investigations: History, exam & CT scan chest &

abdomen

Complete blood count &differential

Serum chemistry Liver, Kidney,

Electro. & Ca+

Pulm.FT & Mediastinoscopy for

surgery.

PET Scan.

Multiple Mutations..oncogene activationcancer.

KK--RasRasCC--mycmyc

p53p53

Irritation Carcinogens Initiation Promotion Ca.

KK--RasRas

MetaplasiaDysplasia Neoplasia

Normal Hyperplasia Metaplasia

Dysplasia Mild Severe Dysplasia Malignancy

Cilia

Goblet cell

Nucleus

Loss of Cilia

& Columnar cells

Cell death.

Stratified Squamous

Epithelium (metaplasia)


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Lung cancer AP view

Lung cancer Lateral view

CT squamous cell carcinoma (NSCC

bronchogenic) central location

Adenocarcinoma peripheral (unlike squamous)

Squamous Cell Carcinoma (NSCC)- M>W

- Highly associated with smoking- Most arise near the hilum, and big bronchi

(CENTRAL) LARGE AIRWAYSMicro- Dysplasia and carcinoma in situ- Thickening and irregularity of the

bronchial mucosa may be seen with abronchoscope

- Prominent keratin production andintercellularbridges

Macro- Often have prominent necrosis and may

cavitate- Tend to spread locally and metastasize

later than other patterns

Central near hilum + cavitate

Origin in main bronchus

Spread

ClearMargin

Smoke

rslung


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Cavitation in squamous cell carcinoma

Microscopy

IF PINK SQUAMOUS CELL KERATIN!!!

CYTOLOGY (above) rest = microscopy

Keratin pearls large nests of Keratin

Note: pink (keratinized) cancer cells (dysplastic)


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Adenocarcinoma- Less associated with smoking than

squamous or small cell carcinomas, butmost

- 75% patients have a history of smoking

- Most common type of lung cancer inwomen and nonsmokers!

Gross- Peripherally located; may be associated

with a scarMicro

- Gland formation mucus- more well differentiated- Columnar or cuboidal cells with

pleomorphic nuclei, often large nucleoli- 80% contain mucin (MUCUS)Cytology- Round/ oval/cuboidal cells

- Blue!- Prominent nucleiExamin with needle biopsy as in periphery oflung! SMALL AIRWAYS

Peripheral adenocarcinoma

Peripheral Adeno

Peripheral adeno a non-smoker woman!


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Cytology

- Cuboidal cells

- Glandular shapes/ formation- BLUE! colour

- Glands- Lumen filled with mucin- Vacuolated

Glandular, cuboildal, mucus

Bronchoalveolar- A subtype of adenocarcinoma- peripherally located - arise in terminal

bronchioles or alveoli- Show appearance on CXR like

pneumonia extensive invasion of lung- Any age, both sexes equally.

Morphology:- Multiple diffuse nodules more like

pneumonia- Columnar-to-cuboidal epithelial cells that

line up along alveolar septa withoutdestruction.

- tall columnar to cuboidal epithelial cells(differentiation along linesof mucin-secreting bronchiolar cells, Clara cells,and/or type II pneumocytes)

- Malignant cells grow along septal wall ofalveoli without invading them

Clinical- Cough, hemoptysis, and pain, but

atelectasis and emphysema areinfrequent.

- Metastases are not widely disseminatedand do not occur early;


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- Overall survival rate is approximately25%.

Note:- Adenocarcinoma can progress to this- Cancer cells IN the alveoli (the cells that line

up along alveolar)- Show bronchopneumonia like diffuse

consolidation (NOT the tumour but theinflammatory response causes this)

-

The tumor cells diffusely infiltrate the alveolar

spaces mimicking a pneumonic process

Malignant cells grow along alveolar septumwithout disturbing it


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Atypical adenomatous hyperplasia(AAH):

o A form of Adenocarcinomao Cytologic atypia is less marked

o Typically


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Bronchogenic Mesothelioma (pleural)

Small Cell Lung Carcinoma (SCLC)- >95% smokers- centrally located masses near hilum

- invade/extension into the lung

parenchyma early spread to hilar

and medistinal lymph nodes- Aggressive and invasive metastatis

widespread

Paraneoplastic syndrome- These tumors are derived from

neuroendocrine cells of the lung =they express a variety ofneuroendocrine markers

- SLCC secrete neuroendocrinal paraneoplastic syndromes

Macroscopic- LARGE central airways- 70% of cases present as perihilar

mass- Extensive lymph node metastases are

common- Typically peribronchial; endobronchial

lesions are uncommon

- neuroendocrine differentiation

Microscopic

- SMALL cells- Round to fusiform shape (look like

lymphocytes) reduced cytoplasm +large relative hyperchromatic neuclei(nuclei>cytoplasm)

- Salt/ pepper granulated chromatin- nuclear molding; faint or absent

nucleoli; scant cytoplasm- Extensive necrosis

Three histologic categories:o Small cell

o Mixed small cell/large cell

o Combined small cell/adeno- or

squamous cell Carcinoma

SCLC affecting the hilar lymph nodes +bronchus

Infiltration pattern around major bronchus - Irregular border

- Spread along bronchus lymph nodes

Infiltration pattern around bronchusNote: black spots in lung = smokers lung

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SCC some bronchiactiac changes

Large nuclei compared to cytoplasmRound small cells

Cytology

Oat cells SCC- BAL bronchio-alveolar lavage fluid.- Gets sample of cells with brush during

bronchoscopy and stained for visualization

- Small Cell Barely any cytoplasm andmostly purple nucleus (cells are bigger thanlymphocytes)

Large nuclei

Looks like inflammatory cells

Carcinoid Tumours

Overview


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Bronchial Carcinoid Tumour:

Note: Benign gross appearance. Round cell clusters.

(Neuroendocrine cells)

- Slow growing, malignant tumour offrom cells of the neuroendocrinesystem.

- 1% to 5% of all lung tumors- Mainly occur in individuals

morphological variants of lung cancer

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