Organ Pathology

Respiratory System - I

Jaroslava Dušková

Inst. Pathol. ,1st Med. Faculty, Charles Univ. Prague

Disorders of lung airiness

Lung Function

oxygenation

carbon dioxide excretion

normal aeration of the lung tissue - conditio sine qua non

Disorders of Lung Airiness

- atelectasis / collaps

+ emphysema

coexistent in many pathology conditions !

Atelectasis / Collaps Def.:

(cz) : A: inadequate expansion C: secondary loss of airiness

(irrespective of age)

(eng): A: inadequate expansion A: loss of lung volume

Atelectasis in ChildrenInadequate expansion:immature lung tissue – insufficient

surfactant (S) production Clinical manifestation - RDSRegulation of (S) synthesis:

corticoids, thyroxine insuline

The main events and outcomes in ARDS

Atelectasis (collaps) in Adults - causes

obstruction

compression

microatelectases

contraction

chest wall

restriction

flail chest

Atelectasis (collaps) in Adults – causes I

obstruction – mucopurulent plug (infection,

mucoviscidosis), bronchomalacia –bronchiectasis, chronic bronchitis, astma foreign body, neoplasm (pores of Kohn)

compression – fluid, air, neoplasms in the pleural cavity

microatelectases – loss of surfactant

contraction – loss of lung elasticity mostly following fibrosis

Atelectasis (collaps) in Adults – causes II

chest wall restriction (obesity, scoliosis)

flail chest (several broken ribs)

Mucoviscidosis cystic fibrosis, fibrocystic disease

autosomal recessive 7th chromosome2-5% heterozygotic carriers in the caucasian

population abnormal viscosity of mucin

– disturbance of the membrane associated protein that serves as a calcium channel

increased concentration of chloride in sweat decreased water content in excocrine secrets

Mucoviscidosis cystic fibrosis, fibrocystic disease

Complications:– meconium ileus– steatorrhea– pancreatic fibrosis & cysts– bronchitis, bronchopneumonia,

bronchiectasia– sterility

Bronchiectasis

Def.:

persistent abnormal dilation of the bronchus.

Types: – cylindrical– saccular

Chronic Obstructive Airways Disease COAD

limitation to airflow in the lungs due to:– airways resistence increased – narrowing– loss of elastic recoil

Diseases of COAD type: chronic bronchitis asthma emphysema

Chronic obstructive pulmonary disease (COPD)

Def.:

chronic productive cough lasting at least three months during two subsequent years

Causes: SMOKING, air pollution

Chronic Bronchitis

Morphology:

– hyperplasia of mucin producing goblet cells (1GC :7CC 1GC:1CC)

– epithelial hyperplasia (& dysplasia!)– inflammatory infiltrate

AsthmaDef.:

a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role,

in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophils, and epithelial cells.

AsthmaClinical manifestation: recurrent episodes of wheezing breathlessness chest tightness, coughing at night or in the early morning

Prologed attack – status asthmaticus

Intrinsic abnormal

β-adrenergic reaction IgE normal causes:

– coolness– effort– infection– aspirin…

Extrinsic type I hypersensitivity IgE causes:

– dust– pollen– animal fur– drugs– foodsuff….

Asthma - types

Asthma

Morphology: bronchial lumina blocked by viscose

mucus and exudate with eosinophils oedema and infiltration of the mucose thickening of the muscle layer and

basement membraneSputum:

– Charcot-Leyden crystals derived from eosinophils– Curshman spirals – glycoproteins– Creola bodies

Start in childhood, evidence of atopyAllergens - household dust, organic dusts, pollens – grasses and trees, animal fur, food products, drugs Reagin – mediated type I hypersensitivity reactionSerum IgE increased, Skin tests against antigens positive Mast cell degranulation – histamin, bradykininSmooth muscle contraction, hyperemia, edema, eosinophils, mucus retention Leukotrines, prostaglandins – brochoconstriction vasodilatation, incr. permeability.

Extrinsic allergic astma

Start in adult life, no evidence of atopy

Hyperactivity of airways is response to nonspecific

stimuli e.. Aspirin, cold, exercise…..

Constriction of bronchial wall

IgE levels normal, skin test normal

Associated with nasal polypi and bronchitis

Pathogenesis – abnormal β-adrenergic response

Intrinsic nonallergic astma

Emphysema

Def.:

Increased airiness of the lung tissue

Abnormal permanent enlargement of gas exchange airways (?

Emphysema

Types: non destructive (overinflation) destructive

–centriacinar (smoking, chronic

bronchitis…)–panacinar (α1- antitrypsin

deficiency)

Smoking & Emphysema numbers of neutrophils &

macrophages in smokers elastase activity macrophage elastase not blocked by

α1- antitrypsinoxygen free radicals in smoke inhibit α1-

antitrypsin

barrel chest, hypertrophy of

intercostal muscles

dyspnea, prolonged

expiration

productive cough (if infected)

Emphysema - clinical symptoms

pneumothorax polycytemia cor pulmonale

Emphysema - complications

Macroscopy cushion- like light pink voluminous pericardium overlapping bullae

Emphysema - morphology

Microscopy alveolar distension centriacinar panacinar

– thinning and destruction of alveolar septa

reduction of capillary bed

Emphysema - morphology

Def.: Entrance of air into the connective tissue of the lung, mediastinum and soft tissue

Interstitial emphysema

Pathogenesis:

spontaneously increased intraalveolar pressue

(cough, violent vomiting) iatrogenous - in patiens on respirator

traumatic - lung trauma – fractured ribs

Interstitial emphysema

Symptoms

swelling of the neck and

head

crackling crepitation

Interstitial emphysema