Tumours of the Lung Flashcards
Lung cancer’s ranking in terms of commonly diagnosed cancers?
Most frequently diagnosed cancer in the world
Lung tumors etiology?
Carcinogenic in nature
172,000 in US, vs 18,000 in 1950s
What is the age of diagnosis of lung cancer?
40-70 years of age
Survival rate of lung cancer?
41%= 1 year survival
15% after 5 years (regardless of stage)
What are common carcinogens involved in lung cancer?
- Tobacco: 87% relationship, women, higher incidence with higher pack years.
- Industrial hazards: radiation, asbestos, etc.
- Air pollution
What are precursor lesions involved in lung cancer?
- Squamous dysplasia and carcinoma in-situ.
- Atypical adenomatous hyperplasia.
- Diffuse neuroendocrine cell hyperplasia.
Histological classifications of lung tumours
- Squamous cell carcinoma (SCC): 25%-40%
- Small cell (oat cell) carcinoma: 20-25%
- Adenocarcinoma: 25-40%
- Large cell carcinoma (large cell neuroendocrine: 10-15%
- Adenosquamous
- Carcinoid (typical and atypical)
- Salivary gland-type (carcinomas)
- Pleomorphic/sarcomatoid/sarcomatous
- Unclassified
Most common lung tumour locations:
- Hilum: 1st-3rd order bronchi
2. Alveoli/terminal - adenocarcinomas (bronchiolaveolar type)
What is the progression of lung cancer in bronchial mucosa?
Goes from a dysplastic lesion to a small, wart-like nodule of bronchial mucosa.
What is the progression in terms of the bronchial lumen?
Fungate into bronchial lumen (aka Intraluminal mass)
What is the progression of lung tumours in terms of the tissue?
Penetrates bronchial wall and extend into peribronchial tissue.
*Carina and mediastinum
Shape of intraparenchymal mass in lung tumour progression?
Creeps along to form a cauliflower-like intraparenchymal mass
Characteristics of small cell cancer (SCC)
- Men
- Smoking history >98%
- Central location (smokers): segmental and subsegmental bronchi
**peripheral incidence is increasing
(Slide 9 for photo)
What role does P53 play in the genetics of SCC?
- NO bearing on prognosis
- Early alterations (overexpression and mutations, less common)
- Increases throughout precursor development.
* 10-50% dysplasias
* 60-90% high grade dysplasia
RB in SCC?
Tumour suppressor gene
15%
P16 in SCC?
CDK-inhibitor
It’s inactivated 65% of the time
Allelic losses in SCC?
Tumor suppressor genes lost
Precede dysplasia ***
3p, 9p, 17p
EGFR role in SCC?
Overexpressed 80% of the time
RARELY mutated
*Epidermal growth factor
Her-2/neu role in SCC?
30%
Without gene amplification (breast)
*Human epidermal growth factor 2, oncogene
What happens in adenocarcinoma?
Glandular differentiation/mucin
foto slide 12
Growth patterns of adenocarcinoma?
- Pure or mixed
- Acinar
- Papillary
- Bronchioalveolar**
- Solid with mucin
What is the etiology of adenocarcinoma?
- Most common tumor in women and non-smokers (75%)
- Peripheral location: smaller
- 80% with mucin
- Slow growing
- Metastasize early and widely***
KRAS’ role in Adenocarcinoma (ACa) genetics?
5% in non-smokers
30% smokers
*RAS subfamily, control of growth factors, mutated in cancers
Other genetic markers found in ACa?
P53
RB
P16
Characteristics of bronchioalveolar cancer?
Found in bronchioalveolar regions
1-9% lung tumours
General location of bronchioalveolar cancer (BAC)? (photo slide 15)
Peripherally located
Can be single or
Multiple nodules (MC): coalesce–>pneumonia-like (slide
Morphology of BAC?
Solid, grey-white with translucent secretions
Rarely: atelectasis/emphysema
Where does BAC arise?
From atypical, adenomatous hyperplasia (monoclonal)*
Kind of spread of BAC?
Lepidic (along alveolar/BA walls); scaly
Like butterflies on a fence
Non-destructive (doesn’t invade underlying architecture).
Cells affected by BAC?
Bronchiolar cells
Clara cells (protect lining, secrete GAGs)
Type II pneumo’s
What is mucinous BAC like?
Tall columnar cells filled with mucin.
Aerogenous spread with: satellite tumors, coalesce.
What is non-mucinous BAC like?
Columnar/peg-shaped/cuboidal cells.
Grow along alveolar septae
Rare aerogenous spread: resectable*
Small cell carcinoma epidemiology ?
1% non-smokers
No pre-invasive phase*
**Most aggressive, earliest to metastasize, and no surgical option
15-25% cure with chemo and radiation
SCC location ?
Major bronchi and peripheral
SCC histologic characteristics? (photo A slide 19)
Highly malignant
- Clustered growth
- Scant cytoplasm imparting blue cells appearance
- Ill-defined cell borders
- Granular (salt and pepper)
- Absent nucleoli
- Neurosecretory granules
Histologic characteristics of SCC (slide 20, b)
- Round, oval, or spindle-shaped cells
- Nuclear molding
- Apoptosis
- Smaller than resting lymphocytes
- Necrosis
SCC genetics?
P53: mutated 50-8-%
RB: mutated 80-100%
BCL2 by IHC in 90%
Large cell carcinoma characteristics (slide 22)?
Undifferentiated Lacks squamoid, glandular, or SCC features Large nuclei Nucleoli Moderate cytoplasm
Secondary pathology of tumours of the lung
- Partial obstruction: focal emphysema
- Total obstruction: atelectasis
- Suppurative/ulcerative bronchitis
- SVC compression
- Pericarditis
- Pleuritis
Lung tumours: paraneoplastic syndromes
- ADH: SCC
- ACTH: SCC
- PTH, PTH-related peptide, prostaglandin E, cytokines
- Calcitonin (hypocalcemia)
- Gonadotropins (gynecomastia)
- Serotonin and bradykinin (carcinoid)
Pleural effusions are seen in what?
Primary or secondary disease
Normal pleural effusions:
15 cc serous lubricating fluid
Acellular and clear
Pleural effusions with increased hydrostatic pressure?
CHF
Pleural effusions with increased vascular permeability?
Pneumonia
Pleural effusions with decreased osmotic pressure?
Nephrotic syndrome
Pleural effusions with increased negative pressure (intrapleural)?
Atelactasis
Pleural effusions with decreased lymphatic drainage?
Mediastinal carcinomatosis
Characteristis of pleural effusions in inflammatory conditions?
- Serous, serofibrinous, fibrinous: infections, SLE, uremia, metastases.
- Empyema: bacterial or mycotic seeding.
- ->loculated, yellow-green creamy pus
- ->small to large volume
- ->exudate: usually organizes (adhesions) - Hemorrhagic pleuritis: sanguineous inflammatory exudate.
- -> look for exfoliated tumour cells
Non-inflammatory pleural effusions ?
- Hydrothorax (serous)
- Hemothorax
- Chylothorax
Hydrothorax (serous) effusions
- Cardiac failure (congestion and edema)
- Uni or bilateral
- Without loculations (bridging fibrosis)
- Basal (atelectasis/compression)
- Resorbed with underlying cause
Hemothorax effusions:
ruptured AA, or vascular trauma
Chylothorax effusions:
milky fluid: lymphatics Emulsified fats Usually left-sided Smaller Thoracic duct trauma (MCC) Tumour
Pneumothorax: details
- Air or gas in the pleural cavity
- MC- emphysema, asthma, and TB
- Spontaneous (rupture of alveolus): abscess cavity (interstitial emphysema)
- Traumatic: perforating chest wall injury
Spontaneous idiopathic pneumothorax:
young ppl
Blebs*: apical/subpleural
Recurrent
Tension pneumothorax:
flap valve (inspiration w/out exit)=pressure pump. May compress vital organs and functions
Pleural tumours: types?
- Primary (RARE): solitary, fibrous tumours; malignant mesothelioma
- Secondary (WAY more common): lung, breast
Solitary fibrous tumours: what are they?
Soft-tissue tumours: pedicle attachment to pleura.
Do NOT produce effusion
Dense fibrous tissue with occasional cysts.
Rarely malignant: mitoses, necrosis, pleomorphism.
IHC: CD34+, KERATIN –
What is mesothelioma?
Happens in visceral or parietal pleura. Due to asbestos 7-10% in high-exposure (life-time) groups. Latent period :25-40 years Smokers and non-smokers
Gross characteristics of mesothelioma? Slide 33
Plaques
Effusions
Invasion
Mesothelioma epithelioid characteristics? Slide 44
- Tubular or papillary structures
- +acid mucopolysaccharide
- +CEA/epithelial GAGs (ACa)
- Strong keratin staining: perinuclear vs. peripheral
- Calretinin, WT1, CK 5/6, mesothelin, thrombodulin
Upper airway inflammation: infections
Adenovirus, echovirus, rhinovirus
Bacterial: mucopurulent to suppurative exudate
Upper airway inflammation due to allergies/hay fever
Pollen Fungi Animals Dust mites IgE mediated
Upper airway inflammation due to nasal polyps:
Cumulative bouts
Ulceration
Chronic upper airway inflammation:
origin independent
deviation
Sinusitis:
impaired drainage
Frontal> anterior, ethmoid
Mixed flora
Kartagener syndrome
Necrotizing upper airway due to :
Fungal infection (mucormycosis)
Wegener’s
Lymphoma
Laryngeal issues:
Laryngitis
Laryngeoepiglottitis: H. influenza or B-strep
Croup: inspiratory stridor, heavy smokers