Histopath Flashcards
which cells are associated with acute inflammation v chronic inflammation (histpaht)
neutrophils - acute
Lymphocytes and plasma cells - chronic
Bilobed nucleus with red granulocytes
Eosinophils
Eosinophils are associated with (3)
Allergic reactions
Parasitic infections
Tumours e.g. Hodgkin’s - they are reactive processes to tumourgenesis
Cell with very large granules containing inflammatory mediators
mast cells
associated with allergic reactions
Lots of cytoplasm, associated with late acute and chronic inflammation
Macrophages
primary role is to phagocytose debris
secondary role to secrete the inflammatory mediators
A true sputum sample will contain macrophages - T/F
T
Even in non-smokers, because marcophages are need to clear up any inhaled pollutants including industrial fumes and especially cigarette smoke
2 features of squamous cell carcinomas
Keratin production + intracellular bridges
2 features of adenocarcinomas
Glands and mucin production
You can stain for mucin using special stains which cause goblet cells to appear bright blue
Name the stain for melanin
Fontana stain - chemical reaction with melanin that makes it more pigmented (appears black)
histochemical stians v immunohistochemical stains?
name examples (*2-3 each)
histochemical is based on CHEMICAL reaction between stain and tissue e.g. H&E, Prussian blue for iron, congo red for amyloid
immuno stain is based on antigen and antibody interaction e.g. immunofluorescence or immunoperoxidases e.g .CD45 (pan-lymphocyte stain), cytokeratin (stain for ketarin used in SCC)
Staining for amyloid (2)
Congo red + apple green birefringence under polarised light
Sheets of plasma cells
Lymphoma
Langerhan type giant cell
Granulomas formed by activated macrophages
Resembles both stratified squamous and stratified cuboidal depending on degree of organ stretch
Transitional epithelium
Seen in bladder, ureters and part of urethra, allows the bladder to expand and contract when needed
Smokers cancer type
Squamous cell carcinoma (also the most common lung cancer overall)
Non-smoker lung ca
Adenocarcinoma (more peirpheral)
Smoking is most associated with these 2 types of lung ca
SCC and small cell carcinoma
*Adenocarcinoma is more in non-smokers
Types of histology samples for a ?lung Ca
- Biopsy at bronchoscopy
- Per-cutaneous CT guided biopsy for peripheral tumours
- Mediastinoscopy and lymph node biopsy for staging
- Open biopsy at time of surgery
- Resection specimen - confirm full excision and staging
Pathogenesis of lung SCC
Normal epithelium -> hyperplasia -> squamous metaplasia -> dysplasia -> carcinoma in situ -> invasive carcinoma
- Tends to arise from proximal airways
- Smoking irritates epithelium which undergoes hyperplasia in response
- No cilia on the airways and deposits of carcinogens from cigarettes stays there
- Metaplasia is characterised by instability which increases risk of accumulating mutations → dysplastic changes
- Stopping smoking can reverse these genetic changes
- But when threshold of mutations reached, cells form carcinoma in situ
- Breakthrough of basement membrane → invasive carcinoma
- Hirsch et al 2001, at each stage, there is accumulation of specific genetic mutations
Clinical features of lung SCC
- who gets it
- Risk factors
- site
- behaviour
Smokers
Usually centrally located, arising from bronchial epithelium
Local spread, mets late
This specific type of lung Ca shows prominent capillary loops underneath dysplastic epithelium
- there is keratinisation and intercellular bridges
angiosqaumous SCC
specific type of SCC, sen in high risk smokers, clinical significance is uncertain
Histology of SCC
Keratinisation
intercellular ‘prickles’ representing desmosome
Adenocarcinoma clinical features
- who gets it
- Risk factors
- site
- behaviour
*BONUS QN: what is a new targetted therapy for adenoCa
Non-smoker, usually females, far east
site: peripheral and often multi-centric, specifically arises from terminal alveoli wall
behaviour: mets early and common, especially extra-thoracic, 80% present with mets
Tarceva (anti-EGFR) which is the most common mutation in adneoCa for non-smoker.
*smoker version of kras, p53 = useless
precursor cells of lung adenoCa
what is the pathogenesis
Atypical adenomatous hyperplasia
Normal terminal alveoli wall lined by type 1 pneumocytes -> develop atypically into type 2-like pneumocytes with large nuclei -> these abnormal cells then grow like a caterpillar along the alveoli wall (adenoCa in situe) -> acquires invasive phenotype to break through basement membrane by destroying elastin
Histological features of adenoCa lung
Desmoplasia with angular glands and single cell infiltration - acinar pattern
(desmoplasia is stained pink)
Glandular differentiation+ mucin production
In medicine, desmoplasia is the growth of fibrous or connective tissue. Desmoplasia may occur around a neoplasm, causing dense fibrosis around the tumor, or scar tissue (adhesions) within the abdomen after abdominal surgery.
Cytological lung adenoCa
Mucin vacuoles
Molecular pathways of adenoCa (2)
Smokers
- kras -> DNA methylation -> p53
Non-smokers
- EGFR amplication/mutation
The two are mutually exclusive
large cell carcinoma lungs
- who gets it
- Risk factors
- site
- behaviour
Rare, poorly differentiated tumours
Site: peripheral or central
Behaviour: poor prognosis
no idea what is the original cell, histology shows no differentiation into squamous (keratin) or adeno (glands + mucin).
Electron microscopy may show some glandular/squamous differentiation.Thought to be due to very poorly differentiated adenoCa or SCC
Small cell carcinoma lungs
- who gets it
- Risk factors
- site
- behaviour
SMOKERS
site; central bronchi (as with SCC)
behaviour: abysmal prognosis, 80% present with BULKY primary and mets. Even when treated (small cell is chemosensitive) tend to recur
ASSOCIATED WITH PARANEOPLASTIC SYNDROMES (ESP SIADH)
Lung Ca + SIADH
small cell carcinoma lungs
two of the most common are humoral hypercalcemia of malignancy (HHM) in squamous cell carcinoma and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in small cell lung cancer
Lung Ca + hyperCa
SCC with PTHrP
two of the most common are humoral hypercalcemia of malignancy (HHM) in squamous cell carcinoma and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in small cell lung cancer
Mutations in small cell Ca of lungs (2)
p53 and RB1
Lung Ca that can be treated with chemo
small cell lung Ca
But even so, Ca tend to recur and abysmal outcome
Lung ca with ERCC1 has good prognosis - T/F
F
ERCC-1 is a predictor for poor response to chemo. Cancers with high ERCC1 proteins are able to remove drug-DNA adducts caused by chemo and hence is chemo resistant
*Chemo is only effect for small cell lung Ca
young female with lung Ca, non-smoker
what type of Ca and what new drug can treat it
Likely adenoCa with EGFR mutation cos non-smoker
Drug is TKI (tyrosine kinase inhibitor) that reduces EGFR activity and dramatically shrink tumours.
Drug name is Tarceva.
but 60-70% of patients acquire resistance to TKI by 790M mutation in EGFR
never smoker adenoCa with EML4-ALK mutation
EML4-ALK mutation found in adenoCa which causes gain of function for Alk gene and ALKinase
Therefore although adenoCa, no benefit from Tarceva (TKI) due to no EGFR mutation.
Solid and signet ring patterns
New targeted therapy - ALKinase inhibitor
SVC syndrome in lung Ca
head and arm oedema
oncology emergency
leads ultimately to circulatory collapse
Lymphangitis carcinomatosa
Complication of lung Ca whereby there is diffuse lymphatic spread within the lung
presents with SOB, poor prognostic feature
Paraneoplastic syndromes with lung Ca
SIADH - small cell Cushing's - small cell (ACTH) PTHrP - squamous cell Coagulation defects Myasthenia gravis like picture
Mesothelioma
- who gets it
- Risk factors
- site
- behaviour
- histology (2)
Asbestos exposure
site: pleura
behaviour: fatal
Long lag time between exposure and disease but dismal prognosis
Histology
- Epithelioid type
- Sarcomatoid type
Both are poor prognosis
Explain the pathology behaviour pulmonary oedema and iron-laden macrophages
Pulmonary oedema is usually caused by LVF or alveolar injury e.g. inhalation of fumes.
because of the damage from fumes, poteineous fluid leaks into the alveolar spaces (where the air usually goes).
In the case of LVF, there is backpressure into the lungs, leading to haemorrhage into the alveolar spaces.
The red cells in the alveolar is mopped up by macrophages which become iron rich (staining blue)
therefore presence of iron-laden macrophages in the lungs are also know nas heart-failure cells
Common point between adult ARDS and infant RDS
Infant RDS = hyaline membrane dx of the newborn
BOTH CAUSES DIFFUSE ALVEOLAR DAMAGE although by diff mechanism
Adult due to cytokine activities destroying the alveolar lining
infants due to insufficient surfactant from prematurity
Macroscopic and microscopic pathology of diffuse alveolar damage
Macroscopic
- expanded, firm solid lungs
- plum colour, airless
- weight >1kg
Microscopic
- proteinaceous fluid in alveolar spaces which impairs gas exchange
- exudate becomes organised and lung tries to repair itself by forming granuloma tissue
Outcomes of diffuse alveolar damage
40% death
superimposed infection
Health and recovery but with permanent fibrosis and residual scarring (in infants known as bronchopulmonary dysplasia)
histological features of acute asthma + correlate these to clinical features of acute asthma
histology
- dilated blood vessels - hyperaemia
- increase number of goblet cells
- oesinophilia
Clinical
- leaky capillaries & airway oedema
- increased mucus production
- bronchospasm
histological features of chronic asthma + correlate these to clinical features of acute asthma
Histology
- airway smooth muscle hyperplasia + remodelling
- mucus plug
- epithelial damage!
Clinical
- SOB
- SOB
Def chronic bronchitis
Chronic productive cough most days for at least 3 months over at least 2 consecutive years
Reid index
Defined as ratio of thickness of submucosal mucus secreting glands:thickness between epithelium and cartilage
<0.4 is normal
> suggest bronchitis
histological features of chronic bronchitis
goblet cell hyperplasia + permanently dilated airways
Causes of emphysema (4)
- smoking
- alpha-1 anti-trypsin def (blocks elastase, in def, overactive elastase destroy alveolar walls)
- IVD
- marfans
patterns of emphysema in smoking v alpha1 anti-trypsin deficiency
Smoking -> centrilobular (loss centered around bronchiole, not so much alveolar terminal air sacs)
Alpha1 anti-trypsin -> panacinar (diffuse loss)
Type 1 v type 2 respiratory failure
type 1 is hypoxia with hypercapnia
Type 2 respiratory failure is caused by inadequate alveolar ventilation; both oxygen and carbon dioxide are affected
COPD blue bloaters, v pink puffers
blue bloaters = chronic bronchitis
pink puffers = empysema
Bronchopneumonia v lobar pneumonia
- who gets each type
- causative organism
- histological features
bronchopneumo
- elderly pt, underlying COPD
- low virulence organisms e.g. staph, haemophilus, strep, pneumoccocus
- fairly extensive dx but localised around the airways
- histology: patchy peribroncho distribution usually in lower lobes
lobar pneumonia
- young, fitter pit
- high virulence organism e.g. S.pnaeumonia
- histology; widespread, fibrinosuppurative consolidation
Congestion, red hepatization, grey hepatization, resolution
progress of lobar pneumonia
initially congestion with hyperaemia/intra-alveolar lfuid
red hepatization - neutrophils in alveolar
grey hepatisation - connective tissue
resolution - fibrosis or completely repair
Rare nowadays with antibiotics
histology of atypical pneumonia
not lobar or bronchopneumo
INTERSTITIAL inflammation
- no alveolar inflammation
- inflamamtion within the septa with oedema +/- viral inclusion bodies on histology (if viral cause e.g. influenza, CMV)
Define granuloma
Collection of macrophages +/- multinucleate giant cells
Lung histology of this pt shows discrete epithelial and giant cell granulomas, mostly in the upper zones.
Granulomas are non-caseatin gand also found in the lymph nodes.
Diagnosis + what investigation?
Sarcoidosis
- idiopathic grnaulmatous disease
diagnose by biopsy - non-necrotising granulomas + elevated ACE
Classify the causes of pulmonary HTN
Pre-capillary
- vasoconstrictive
- embolic
Capillary
- pulmonary fibrosis causing mechanical vascular distortion and chronic hypoxia
post-capillary
- left-sided heart disease
Def pulmonary HTN
mean pulmonary arterial pressure >25mmhg at rest
Abstesto affects the upper/lower lobes of the lungs
Inorganic dust e.g. coal workers lung and silicosis affects the upper/lower lobes of the lungs
Abstesto affects the LOWER lobes of the lungs
Inorganic dust e.g. coal workers lung and silicosis affects the UPPER lobes of the lungs
young’s syndrome
Rhinosinusitis
azoospermia
bronchiectasis
a) Cryptogenic Fibrosing Alveolitis / Idiopathic Pulmonary Fibrosis
● M>F
● Causative agents unknown
● Histological pattern of fibrosis = Usual Interstitial Pneumonia, required for diagnosis
(also seen in connective tissue disease, asbestosis and EAA)
o Progressive patchy interstitial fibrosis with loss of normal lung architecture and
honeycomb change, beginning at periphery of the lobule, usually sub-pleural o Hyperplasia of type II pneumocytes causing cyst formation – honeycomb
fibrosis.
● Can have inflammatory cause e.g. RA, SLE, systemic sclerosis
● Clinical presentation: increasing exertional dyspnoea and non-productive cough. 40- 70y at presentation, with hypoxaemia cyanosis and pulmonary HTN +/- cor pulmonale, and clubbing.
● Rx: steroids, cyclophosphamide, azathioprine, but little impact on survival
b) Pneumoconiosis
Typically an occupational lung disease; a non-neoplastic lung reaction to inhalation of mineral dusts or inorganic particles. The majority of pneumoconioses affect the upper lobe. e.g. coal worker’s pneumoconiosis, silicosis, asbestosis.
NB: asbestosis can cause benign pleural lesions (plaques, fibrosis) but can also cause malignant lesions (adenocarcinoma, mesothelioma). Asbestosis tends to affect the lower lobe.
Paraneoplastic syndromes: ADH → ACTH → PTH/ PTHrP → Calcitonin → Serotonin → Bradykinin →
Paraneoplastic syndromes:
ADH → SIADH
ACTH → Cushing’s syndrome
PTH/ PTHrP → primary hyperparathyroidism, hypercalcaemia and bone pain
Calcitonin → hypercalcaemia
Serotonin → carcinoid syndrome (flushing + diarrhoea + bronchoconstriction)
Bradykinin → cough
Day 1 post MI histo + cardiac enzymes
Microscopic histo:
- coagulation necrosis, loss of nuclei and striations
- neutrophils
Gross histo: no changes
Enzymes
- high CK, high trop, normal myoglobin (normal by 24 hours)