Chapter 1 Flashcards
Where are the pores of Kohn?
Perforating the alveolar walls
What is the function of the pores of Kohn?
Permit passage of exudate and abcteria between adjacent alveoli
What are 5 conditions for the lungs to freely exchange oxygen and carbon dioxide? State an example of a disease that compromises each condition.
- Alveoli Open - pneumothorax
- Lungs must be compliant - scarring of lung
- Air must move freely - asthma
- Sufficient area for diffusion - COPD/Emphysema
- Barrier for diffusion must be thin - Chronic fibrosing disease of the lung
What are the two types of rhinitis?
Infective and Allergic Rhinitis
What is the pathogenesis of infective rhinitis?
Viral necrosis of surface epithelial cells resulting in exudation of fluid and mucus from the damaged surface
Submucosal edema produces swelling and nasal obstruction
May spread to lower tract and predispose patient to secondary bacterial infection
What is the pathogenesis of allergic rhinitis?
Hypersensitivity to environment.
What happens when antigenic stimulus persists in allergic rhinitis?
Mucosa becomes swollen and polypoid, with formation of nasal polyps
What is the morphology of nasal polyps?
Multiple, bilateral; involve nasal cavity and paranasal sinuses
What is the histology of nasal polyps?
Localised outgrowths of lamina propria due to accumulation edema fluid, inflammation (amount and composition variable - neutrophil, eosinophil, lymphocytes, plasma cells) and fibroblast proliferation
What is sinusitis?
Inflammation of the paranasal sinus linings of the maxillary, ethmoid and frontal sinuses
What condition is sinusitis associated with?
Rhinitis
What condition are sinusitis patients predisposed to. Explain.
Secondary bacterial infection. Mucosal edema results in impaired drainage of secretions
What is one worrying risk of sinusitis?
Infection can spread to meninges because roof of paranasal sinuses are in direct contact with the base of the brain
What are two benign tumours of the nose/paranasal sinuses
- Squamous papilloma of nasal vestibule
- Sinonasal papillomas
What are squamous papillomas of the nasal vestibule histologically similar to
Viral warts of skin
Describe the appearance of sinonasal papillomas
- fungiform/exophytic or inverted
- Covered by non-keratinising squamous epithelium, ciliated columnar epithelium or intermediate/transitional epithelium
- May have mucus secreting cells
- epithelium may appear oncocytic
What are 4 malignant tumours of the nose and paranasal sinuses?
- Squamous cell carcinoma (most common, anterior region)
- Transitional cell carcinoma (further back)
- Adenocarcinoma
- Malignant Melanoma
What is juvenile angiofibroma?
- Rare tumour in male adolescents
- Benign, but may grow quickly during puberty
- Frequently ulcerate and present with bleeding
Where is Nasopharyngeal Carcinoma (NPC) endemic?
Southern Chinese and migrants from South China
Greenland
Africa
What are the 3 histologic types of NPC?
- Non keratinizing
- Keratinizing
- Basaloid Squamous Cell
Histology of non-keratinising NPC?
- Poorly differentiated
- Intermingled lymphocytes amongst carcinoma cells
Histology of keratinising NPC?
- Intercellular bodies
- Bright pink cytoplasm
- Keratin formation
*resembles squamous cell carcinoma
What is keratinising NPC associated with?
Smoking and alcohol consumption
What are 3 risk factors for NPC?
- EBV Infection at young age
- Salt preserved food
- Family History
Read the link between EBV and NPC
-
What are the symptoms of NPC?
- Obstruction to Eustachian Tube – secretory otitis media = hearing loss & tinnitus
- Diplopia (due to invasion of Cranial Nerve 6)
- Nasal Obstruction, Epistaxis, Serous nasal discharge
- Metastases in cervical lymph nodes
What are two childhood diseases of the respiratory tract that have been eradicated by vaccination? Explain their pathogenesis?
- C. diphtheriae - infects upper airway mucosa, produces exotoxin that causes necrosis of epithelium; pseudomembrane may be aspirated causing airway obstruction
- H. influenzae - acute epiglottitis causing airway obstruction
What are five non-neoplastic conditions that affect the larynx? Explain the pathogenesis.
- Acute pharyngitis and laryngitis
- usually caused by viral infection - Allergic pharyngolaryngeal oedema - life threatening type 1 hypersensitiivty reaction; associated with facial oedema and bronchospasm
- Acute toxic laryngitis - cause of death in fires
- Chronic laryngitis - common in heavy smokers; chronic irritation of epithelium results in squamous metaplasia, increasing risk of dysplasia and squamous cell carcinoma
What are symptoms related to acute pharyngitis and laryngitis?
“Sore throat” = supraglottic
Hoarseness = glottic
cough, tracheal soreness = subglottic/trachea
What is the risk of acute pharyngitis and laryngitis in children?
Airway is small and collapsible so mucosal and submucosal edema may result in airway obstruction
What is stridor?
Due to large airway obstruction, worsened upon inspiration
What is croup?
Children cough & stridor due to infection
What is a complication of upper respiratory tract infection in elderly/debilitated/unconscious patient?
Cough reflex is poor and infected material may not be coughed up but pass into the smaller airways and rest of lung, causing bronchopneumonia=
State and explain two benign lesions of the larynx
- “Singer’s” Nodules - vocal cords damaged = reactive thickening = reactive nodular thickenings of the vocal cords seen in singers and chronic smokers
- Laryngeal squamous papilloma (finger-like protrusions)
- due to infection by HPV
- in adults: usually solitary
- in children: ‘juvenile laryngeal papillomatosis’: multiple soft papillomas affecting larynx and trachea, often persistent and recurrent
What is carcinoma of the larynx associated with?
Smoking
Where does carcinoma of the larynx occur?
Supraglottic, glottic or subglottic
What is the significance of the localisation of the carcinoma of the larynx?
Planning treatment and prognosis
Compare glottic tumours to supra and sub glottic tumours of the larynx.
- Present early (hoarseness)
- Lower stage at presentation due to poor lymphatic supply
How does carcinoma of the larynx appear?
Polypoid (grows into airways) or ulcerative growth patterns
What is the method of spread of carcinomas of the larynx?
Local invasion
Regional lymph nodes
