LUNG pathology Flashcards
Respiratory system is an outgrowth from the____
Ventral wall of the foregut
Midline trachea develops two lateral outpocketings
Lung buds
How many branches arise from the Right lung bud?
3 (lobar bronchi)
How many branches arise from the left lung bud?
2 ( lobar bronchi)
Respiratory bronchioles + alveolar ducts + alveolar sacs
Acinus
3-5 terminal bronchioles + respective acinus
Pulmonary lobule
Histology of bronchial mucosa
pseudostratified, tall, columnar, ciliated epithelial cells
Alveolar epithelium
Flattened, plate-like Type 1 pneumocytes covering 95% of the alveolar surface
Rounded Type II pneumocytes; synthesize surfactant; contained in osmiophilic lamellar bodies
Entire lung and bronchial tree may be absent on one side
Pulmonary agenesis
Incomplete development of the lungs (Presence of rudimentary bronchi but no lung tissue)
Pulmonary Aplasia
Defective development of distal lung tissue of both lungs (can be bilateral but usually one may be more affected than the other)
Pulmonary hypoplasia
Decreased weight, volume, and acini disproportional to the body weight and gestational age
Pulmonary hypoplasia
Causes Pulmonary hypoplasia
abnormalities that compress the lungs or impede normal lung expansion in utero
(CDH and oligohydramnios)
Bowels enter the thoracic cavity and impede proper growth and development of the lung
Congenital diaphragmatic hernia
Abnormal communication between the trachea and the esophagus, Depending on the type, this can lead to severe and fatal pulmonary complications and aspirations
Tracheoesophageal Fistula
Most common type of Tracheoesophageal Fistula
H type variation
Suspected in a newborn baby who frequently coughs or regurgitate milk after bleeding
TEF
Vascular abnormalities
Pulmonary Arteriovenous malformations
Alveolar capillary dysplasia
Pulmonary Lymphagiectasia
Massive overinflation of one or more lung lobes occuring postnatally (compared to adult type emphysema wherin you have actual wall loss)
Congenital Lobar Emphysema
What lobe is mostly common in the congenital lobar emphysema
Upper lobes
Causes of vongenital lobar emphysema
Intrinsic absence or abnormality (bronchomalacia) of cartilaginous ring
External compression by a large pulmonary artery
Compression by a large pulmonary artery ..(Congenital Lobar emphysema)
Bronchi at the involved site may be devoid of cartilahe
Cardiac anomalies may be present
Abnormal detachment of the primitive foregut
Foregut cyst
Most often location of foregut cyst
hilum or the middle mediastinum
Classification of foregut cyst
Bronchogenic (most common)
Esophageal
Enteric
Foregut cyst
lined by ciliated pseudostratified columnar epithelium with squamous metaplasia. Wall contains bronchial glands, cartilage and smooth muscle
Curative for Foregut cyst
Surgical Resection
Also called Congenital Adenomatoid Malformation (CCAM)
Congenital airway malformation
Defect in the development of the terminal bronchioles
Congenital pulmonary airway malformation
Histologic categories of congenital pulmonary airway malformation
Macrocytic (13%)
Microcystic (73%)
Solid Cystic Adenomatoid Malformation (13%)
Macrocystic CPAM
Best prognosis
One or more large (>5mm on prenatal ultrasound) cysts are lined with normal pseudostratified ciliated epithelium)
Microcystic CPAM
Small cysts lined with ciliated columnar or cuboidal epithelium (similar to lining of more distal and terminal airways)
Solid cystic Adenomatoid Malformation
Worst prognosis
Airless Tissue mass composed of cuboidal epithelium lined bronchioles
Presence of a discrete mass of lung tissue without normal connection to the airway system
Pulmonary sequestration
Blood supply of the pulmonary sequestration arise from??
aorta and its branches
External to the lung, and may be located anywhere in the thorax or mediastinum, Obvious separate mass from the main lung lobe, Abnormal mass lesion in infants, associated with other congenital anomalies
Extralobar sequestration
Within the lung substance, Usually in older children, often associated with recurrent localized infection or bronchiectasis
Intralobar sequestration
Mucus gland hyperplasia, Hypersecretion, redi index of >0.4
Chronic Bronchitis
Airway dilation and scarring, necrotizing inflammation of airway
Bronchiectasis
Smooth muscle hyperplasia, excessive mucus inflammation, reversible narrowing/ obstruction of airway
Asthma
Airspace enlargement; wall destruction
Emphysema
Inflammatory scarring, obliteration of bronchioles
Small-airway disease/ Bronchiolitis
Predominant Bronchitis
Age: 40-45 Dyspnea: Mild; late Cough: Early; copious sputum Infections: Common Respiratory Insufficiency: Repeated Cor pulmonale : common Airway Resitance: Increased Elatic Recoil: Normal Chest Radiograph: Prominent vessels;large heart Appearance: blue Bloater
Predominant Emphysema
Age: 50-75 Dyspnea: Severel earlyl classic characteristic for emphysema Cough: Late; scabty sputum Infections: Occasional Respiratory insufficiency: terminal Cor pulmonale: Rare Airway Resistance: Normal Elastic Recoil: Low Chest Radiograph: Hyperinflation; small heart Appearance: Pink puffer
Abnormal permanent enlargement of the airspaces distal to the terminal bronchioles
Emphysema
Destruction of their walls without obvious fibrosis in contrast to overinflation
Overinflation
Enlargement of airspaces not accompanied by destruction
Emphysema types according to its anatomic distribution within the lobule:
Centriacinar
Panacinar
Distal acinar
Irregular
Centriacinar
Clinically significant
20x more common than panacinar
Distal acinar are usually spared
Panacinar
Clinically significant
Distal acinar and irregular types
not clinically significant but are pprone to develop pleural blebs, causing pneumothorax in younger people
Tobacco
causes production of ROS, induce inflammation, increase neutrophils that secrete elastases; ROS also inactivate anti-proteases, activating tissue disruption
Reversible bronchoconstriction, Airway hyperresponsiveness
ASTHMA
Th2 and immunologic reaction to environmental allergens. Has acute phase and late phase
Atopic asthma
Th2 cytokines in atopic asthma
IL-4, IL-5, IL-13
Whorls of shed epithelium
Curschmann spirals
Collections of crystalloids made up of eosinophil proteins
Charcot Leyden crystals
Irreversible component of asthma, Sub basement membrane thickening, hypertrophy of bronchial glands and smooth muscle
Airway Remodeling
Persistent productive cough for at least 3 consecutive months in at least 2 consecutive year
Chronic bronchitis
Hypersecretion of mucus. Airflow obstruction due to (small airway disease and coexistent emphysema)
Hyersecretion of mucus
Morphology of large airway in chronic Bronchitis
Hyperemic and swollen mucosal lining Mucinous or mucopurulent secretions Enlargement of mucus secreting glands Reid index of >0.4 THickness of submucosal gland layer to bronchial wall Chronic and acute inflammation of mucosa Eosinophils not a prominent feature
Morphology of chronic bronchiolitis
Goblet cell metaplasia
Mucus plugging
Inflammation
Fibrosis
Permament dilation of bronchi and bronchioles due to ulcerating inflammation. Caused by destruction of the muscle and elastic tissue
Bronchiectasis
Primary ciliary dyskinesia
Kartegener syndrome
