Human Respiratory System

Components of the Upper Respiratory Tract

FunctionsFunctions:: PassagewayPassageway for respiration. ReceptorsReceptors for smell. FiltersFilters incoming air to filter larger foreign

material. MoistensMoistens and warms incoming air. ResonatingResonating chambers for voice.

Upper Respiratory TractUpper Respiratory Tract

FunctionsFunctions:: Larynx: Larynx: maintains an open airway and assists in sound production.

Trachea: Trachea: transports air toto and fromfrom lungs. Bronchi: Bronchi: branch into lungs. Lungs: Lungs: transport air to alveoli for gas exchange

Lower Respiratory TractLower Respiratory Tract

Components of the Lower Respiratory Tract

DISEASES OF UPPER DISEASES OF UPPER RESPIRATORY TRACTRESPIRATORY TRACT

Immotile cilia (Kartagener) syndrome: Definition: Definition: Congenital defect of ciliary movement. Childhood onset due to defective or non-functional cilia in the respiratory tract → chronic sinusitis, defective mucociliary transport and bronchial clearance, bronchiectasia, chronic Otitis Media and headaches, related to immotility of ependymal cilia in the walls of cerebral ventricles; and absence of frontal sinuses.

Status Of ReproductionStatus Of Reproduction:: ♂♂ are infertile,1⁄2 of ♀ are im-pregnatable, the other1⁄2 sterile.1⁄2 have Kartagener's triad, i.e chronic sinusitischronic sinusitis, bronchiectasisbronchiectasis and situs inversus totalissitus inversus totalis.(A condition in which there is complete right to left reversal (transposition) of the thoracic and abdominal organs)

DISEASES OF UPPER RESPIRATORY TRACT:

Congenital

DISEASES OF UPPER RESPIRATORY TRACT

RHINTIS & SINUSITIS

1. Common cold: viral infection: rhinoviruses, adenoviruses, echoviruses → catarrhal inflammation with mucous discharge. Secondary Secondary bacterial bacterial infection → muco-purulent discharge.

2. Allergic rhinitis (hay fever): Ig E mediated hypersensitivity reaction (type-

I) to plant pollen antigens → Nasal PolypsNasal Polyps. 2ry. infections are common → Chronic Rhintis.

3. Chronic Rhinitis: AEAE:: repeated bacterial infections. P.FP.F.:.: Deviated Deviated Nasal Septum or Nasal Septum or Nasal PolypsNasal Polyps. May → chronic sinusitis.

4. Chronic Sinusitis: Most common bacterialbacterial. .

In DMDM may be fungalfungal (mucormycosismucormycosis). Rarely, it is associated with immotile

cilia (Kartagener’sKartagener’s) syndrome.

A. Low-power magnification showing edematousmasses lined by epithelium.

B. High-power views showing edema and eosinophil-richinflammatory infiltrate.

Nasal polypsNasal polyps

DISEASES OF UPPER RESPIRATORY TRACT

NASOPHARYNGITIS & TONSILLTIS

-AE: viral, or bacterial infection (beta-hemolytic beta-hemolytic streptococcistreptococci)…..???

- Morphology: tonsils are enlarged, red and dotted by dotted by pinpoints of exudate pinpoints of exudate from the tonsillar crypts (follicular tonsillitis).

-Local complications: Otitis Media, peritonsillar abscess

("quinsy")("quinsy"), and tonsillar hypertrophy.

- Remote post-streptococcal complicationsRemote post-streptococcal complications: : Rheumatic Fever (RFRF) and glomerulonephritis (GNGN).

TUMORS OF THE NOSE, SINUSES & NASOPHARYNX

1- NASOPHARYNGEAL ANGIOFIBROMA: Highly vascular benign non-capsulated tumor of adolescent males. EpistaxisEpistaxis+/-

2-INVERTED PAPILLOMA: Locally aggressive neoplasm (high recurrence rate) of the NoseNose or the paranasal SinusesSinuses; rare progression to carcinoma.

3- ISOLATED PLASMACYTOMA: Malignant plasma cell tumor; solitary lesion, rare → to multiple myeloma (MM).

4- OLFACTORY NEUROBLASTOMA: Highly malignant; neuro-neuro-endocrineendocrine tumors of the olfactory mucosa; positive for neuron-specific enolase and S-100 protein.

INVERTED PAPILLOMA: NoseNose..

The masses of

squamoussquamousepithelium epithelium are growing inward; hence, the term inverted.

5- NASOPHARYNGEAL CARCINOMA:

A- Keratinizing squamous cell crcinoma Keratinizing squamous cell crcinoma (WHO-1)

B- Non-keratinizing squamous cell carcinoma Non-keratinizing squamous cell carcinoma (WHO-2)

C- Undifferentiated carcinomaUndifferentiated carcinoma (WHO-3): = Lymphoepithelioma (admixed with dense lymphocytic infiltrate.

-Age: children in Africachildren in Africa & Adults in ChinaAdults in China.

-PF: Epstein-Barr (EBVEBV). Chromosomal.??

-TTT. : TTT. : Unresectable because of widespread metastaseswidespread metastases at the time of diagnosis.

-Undifferentiated carcinoma response better to to radiotherapy radiotherapy than the keratinizing type.

NASOPHARYNGEAL CARCINOMANASOPHARYNGEAL CARCINOMA ))MicroscopicMicroscopic((

(WHO-2)(WHO-3):

LARYNGITIS

AE: AllergicAllergic, viralviral, bacterial or chemical (tobaccotobacco) injury.

Acute laryngitis: AE: viral (Parainfluenza virusParainfluenza virus) or bacteria.

In children → narrowing of the larynx, that causes stridor & in young infants laryngeal edema → airway obstruction & death (Tracheostomy is life saving). Laryngo-tracheo-bronchitisLaryngo-tracheo-bronchitis ( (croupcroup).).

Chronic laryngitis: AE:Cigarette in adults → (dysplasiadysplasia) →

SCC ( Squamous Cell Carcinoma)

LARYNGEAL POLYPS & PAPILLOMAS

Polyps: ( Singer’s Nodule) Small inflammatory nodules on the true vocal cords true vocal cords of signerssigners & teacherseachers; caused by overuse of voice →→ hoarseness. They nevernever give rise to Cancer XXX.

Papillomas: AEAE: HPV-1, Multiple in children.HPV-1, Multiple in children.

Tend to recur after excisionrecur after excision. May →→ Cancer.

True neoplasms; raspberry-like nodules, with delicate finger-like papillae covered by squamous epithelium; liable to fragmentationfragmentation and bleedingbleeding.

LarynxLarynx: S. Node, Papilloma vs. Carcinoma: S. Node, Papilloma vs. Carcinoma

Diagrammatic comparison of a benign Singer’s Singer’s node, papillomanode, papilloma and an exophytic carcinomacarcinoma of the larynx to highlight their quite different appearances.

-Epithelial changes, ranging from hyperplasia, dysplasia, CIS (carcinoma in hyperplasia, dysplasia, CIS (carcinoma in situ) to invasive squamous cell carcinoma.situ) to invasive squamous cell carcinoma.

- Gross: vary from dysplasia, CIS (carcinoma dysplasia, CIS (carcinoma in situ)in situ) to frankly malignant verrucose or ulcerated nodule.

- AE: Cigarette smoking Cigarette smoking is the major causative factor & cessation of smoking causes regression of early lesions. . AsbestosAsbestos & HPVHPV are contributing factors.

-M/E : Squamous cell Carcinoma of varying degrees.

- Prognosis: Carcinomas of the true vocal cord (intrinsic type) is betterbetter than carcinomas above or below the vocal cord .

Sq.C.C in the supraglottic location (above the true vocal cord)

LARYNGEAL CARCINOMA

Laryngeal carcinoma Laryngeal carcinoma (Gross & M/E)(Gross & M/E)

A. Note the large, fungating lesion involving the vocal cord and pyriform sinus.

B. Histologic appearance of laryngeal squamous cell carcinoma.

Note the atypical lining epithelium and invasive keratinizing cancer cells in the submucosa.

LARYNGEAL SQUAMOUS CELL CARCINOMALARYNGEAL SQUAMOUS CELL CARCINOMA

SALIVARY GLANDS

Diseases of Salivary Diseases of Salivary GlandsGlands

A Commitment to A Commitment to ExcellenceExcellence……

SIALADENITIS & SIALOLITHIASIS

Sialadenitis: viral (mumps), bacterial (secondary to ductal obstruction) or autoimmune (Sjogren’s syndrome(Sjogren’s syndrome= xerostomia (Dry Mouth- due to lack of saliva) + keratoconjunctivitis sicca= the sicca syndrome)

Sialolithiasis: dehydration may -> obstruction of the obstruction of the salivary ducts salivary ducts by inspissated food debris → stone formation stone formation & secondary bacterialbacterial sialadenitis (Staph. Aureus & Strept. Viridans). Submandibular salivary gland is most commonly affected; usually unilateral; with symptoms & signs of acute suppurative inflammation.

Causes of Sialadenitis

Infectious

–MumpsMumps (paramyxovirus)

–Bacterial (usually associated with ductal obstruction)

Autoimmune (Sjogren’sSjogren’s)

Sjogren’s SyndromeSjogren’s Syndrome

Immune-mediated destruction of the lacrimallacrimal and salivary glandssalivary glands, often occurring in association with rheumatoid arthritisrheumatoid arthritis (RA) or another autoimmune disorder.

GrossGross: : Xerostomia and keratoconjunctivitis sicca + ..? MEME: shows dense lympho-plasmacytic lympho-plasmacytic inflammatory

infiltrate with destruction of glandulardestruction of glandular tissue.

Sjogren’s syndromeSjogren’s syndrome Etiology and pathogenesisEtiology and pathogenesis

– primary target is ductal epithelial cells of exocrine glands

– B-cell hyperactivity - hypergammaglobulinemia, antinuclear antibodies.

– primary defect is in T-helper cells (too many)– most have anti- RNA (anti -SS-A and anti-SS-B)

antibodies– associated with HLA-DR3

Sjogren’s syndromeSjogren’s syndrome C/P:C/P:

– primarily in women > 40– dry mouthdry mouth, lack of tears.lack of tears.– salivary glands enlargedsalivary glands enlarged.– 60% with other ConnectiveTissue Diseases.other ConnectiveTissue Diseases.– 1% develop lymphomalymphoma, 10% with pseudolymphomas

Sjogren’s syndromeSjogren’s syndrome Pathology:Pathology:

– all secretory glands can be involved

– intense lymphoplasmacellular infiltrates

– secondary inflammation of corneal epithelium (due to drying) leads to ulceration and xerostomia

– can develop respiratory symptoms if these glands are affected

– 25% develop extraglandular disease (most with anti-SS-A) involving CNS, kidneys, skin and muscles

Sjogren’s syndromeSjogren’s syndrome

Intense lymphoplasmacytic infiltrate with ductal epithelial hyperplasia

Sjogren’s syndromeSjogren’s syndrome

Sjogren’s syndrome: PathologySjogren’s syndrome: Pathology

Salivary Glands Salivary Glands Neoplasia Neoplasia

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TUMORS OF THE SALIVARY GLANDS

-Up to 80% arise in the parotid gland 80% arise in the parotid gland (15% malignant), 10% in the submandibular (40% malignant) & 10% in the minor salivary glands (Less than 50% malignant). Affect middle-aged adults, the malignant at an older age than the benign.

- Histological types:

1- Pleomorphic adenoma 45% (benign).

2- Warthin’s tumorWarthin’s tumor 11% (benign)11% (benign)

3- Muco-epidermoid carcinoma 15% (malignancy)

4- Adenoid cystic carcinoma 10% (malignant)

5- Acinic cell carcinoma 03% (malignant)

Pleomorphic AdenomaPleomorphic Adenoma (mixed tumor of salivary gland)

Most common salivary gland tumorMost common salivary gland tumor 45% (Benign45% (Benign). Most often arises in superficial parotid Gross: Circumscribed, glistening, myxoid lesion M/EM/E: : shows heterogeneous mix of ducts, acini, and

sheets of cells in a myxoid or chondroid stroma Complete resection is necessary to prevent recurrencerecurrence

(10% recurrence rate). Low percentage show malignant areas.

Pleomorphic adenoma: Pleomorphic adenoma: Gross:Gross: shows sharply circumscribed, yellow-white tumor protrudes above the level of the surrounding glandular substance.

Pleomorphic adenoma. Pleomorphic adenoma. M/E:M/E: note cartilagecartilage admixed with benign glandular epithelial glandular epithelial elements.

A. Low-power view showing a well-demarcated tumor with normal parotid acini below.

B. High-power view showing amorphous myxoid stroma resembling cartilage, with interspersed islands and strands of myoepithelial cells.

Warthin’s TumorWarthin’s Tumor

Papillary cystadenoma lymphomatosumlymphomatosum or (adenolymphoma). 11% (Benign)

Infrequent benign tumor benign tumor of the parotid gland Well-encapsulatedWell-encapsulated green-brown mass with

cleft-like spaces on the cut surface. Mixture of oncocytic epithelium oncocytic epithelium and subjacent

lymphoid tissue.lymphoid tissue. 10% recurrence rate.

Warthin’s Tumor: Warthin’s Tumor: Papillary oncocytic epithelium + prominent lymphoid componentlymphoid component.

Warthin’s TumorWarthin’s Tumor: A. Lower-power view showing

epithelial and lymphoid elements.

Note the follicular germinal center beneath the epithelium.

B. Cleftlike spaces separate the lobules of tumor covered by a regular double layer of eosinophilic epithelial cells based on a lymphoid stroma.

Mucoepidermoid carcinomaMucoepidermoid carcinoma

A. Mucoepidermoid carcinoma showing islands having squamous cells as well as clear cells containing mucin.

B. Mucicarmine stains the mucin reddish-pink.

Adenoid cystic carcinoma Adenoid cystic carcinoma in a salivary gland.in a salivary gland.

A. Low-power view. The tumor cells have created a cribriform pattern enclosing secretions.

B. High-power view showing polygonal tumor cells surrounding thecystic space filled with secretions.

Carotid body tumor (Paraganglioma)Carotid body tumor (Paraganglioma)..

A. Low-power view showing tumor clusters separated by fine vascular septa(zellballen appearance).

B. High-power view of large, eosinophilic, slightly vacuolatedcells with elongated sustentacular cells in the septa.

THE END