HNS35 NPC And Other Head And Neck Tumours Flashcards
1
Q
Histology of head and neck
A
3 mains types of epithelium:
- Respiratory (main, functional, ***Ciliated Pseudostratified columnar epithelium with Goblet cells)
- Ciliated cells
- Mucous cells - Transitional (non-ciliated epithelium)
- Squamous (main)
- present where there is communication with environment i.e. Oral cavity, Pharynx, Nasal vestibule
- ***Stratified squamous —> resistant to damage / pathogens
Main neoplasm sites: Respiratory / Squamous epithelium
2
Q
***Cause of disease (VINDICATE) in head and neck tumours
A
- Vascular
- Juvenile angiofibroma - Inflammatory
- Nasal polyps - ***Neoplastic
- Nasal neoplasms (Epithelial / Stromal / Lymphoid)
—> Papilloma
—> SCC
—> Malignant melanoma
—> Adenocarcinoma
—> Malignant lymphoma
- Nasopharyngeal neoplasms
—> **NPC (SCC, Differentiated, **Undifferentiated Non-keratinising carcinoma)
—> Sarcoma
—> Lymphoma
- Degenerative (none)
- Infectious
- TB, Leprosy
- Scleroma
- Aspergillosis, Candidiasis - Congenital
- Cleft palate
- Choanal atresia / stenosis - Auto-immune
- Wegener’s granulomatosis - Traumatic / Toxic
- Wood dust associated adenocarcinoma - Environmental / Endocrine
- Allergic nasal polyps
3
Q
Vascular - Juvenile angiofibroma
A
- Juvenile angiofibroma
- Malformation of nasal ***erectile tissue
- Young boys predominant —> develops around puberty and regresses afterwards
-
**Vascular + Fibrous lesion (mass/polyp)
—> well-circumscribed, inflamed, oedematous polypoid mass
—> can lead to **extensive bleeding - Present as Nasal obstruction / ***Intermittent epistaxis
- considered benign tumour —> but can infiltrate surrounding tissue —> extensive destruction
4
Q
Inflammatory - Nasal polyps
A
- Nasal polyps
- Rounded projections of oedematous mucous membrane
- develop in association with Inflammation, Allergy, Mucoviscidosis (cystic fibrosis)
- usually **Allergic in nature
記:
1. **Oedematous fibrous tissue / stroma
2. Eosinophils + Plasma cells (not as vascular as angiofibroma) - ***Goblet cell hyperplasia in respiratory epithelium
- always examine histologically —> more serious diseases e.g. cancer can also present as polyps
5
Q
Infection causes
A
- Tuberculosis, Leprosy
- caseous necrosis surrounded by epitheloid histiocytes - Scleroma (by ***Gram -ve bacilli)
—> chronic bacterial infection
—> granulomatous disease which begins in nose
—> progressively extend into nasopharynx, oropharynx, larynx - Aspergillosis, Candidiasis
6
Q
Congenital causes
A
- Cleft palate (unilateral / bilateral)
- Choanal atresia / stenosis
—> connection between nasal canals and pharynx is blocked completely / partially
—> by soft tissue membrane / bony plate
7
Q
Autoimmune causes - Wegener’s granulomatosis
A
- Wegener’s granulomatosis
- ***Necrotising giant cell granulomas due to Autoimmune cause
—> appear in URT first
—> spread to trachea / lungs
—> along midline - ***Vasculitis (no caseous necrosis)
- Mixture of ***1. Multinucleated giant cells, 2. Histiocytes, 3. Granulation tissue
- Untreated: death within a year
—> associated **Renal arteritis, **Necrotising glomerulitis —> Renal failure - a type of **Lethal midline granuloma
—> a syndrome of a **non-infective destructive lesion of URT
—> include Wegener’s granulomatosis, Conventional malignant lymphoma, Polymorphic reticulosis
8
Q
Traumatic / Toxic causes
A
Wood dust associated adenocarcinoma
9
Q
Endocrine / Environmental causes
A
Allergic nasal polyps
10
Q
***Nasal neoplasms
A
- Epithelial
- Papilloma
- SCC
- Malignant melanoma
- Adenocarcinoma - Stromal (uncommon)
- Lymphoid
- Malignant lymphoma
11
Q
Nasal neoplasms - Epithelial tumours
A
Benign:
- ***Papilloma (squamous / transitional) (HPV-related)
- can recur
- can have inverted papilloma
Malignant:
- ***Squamous cell carcinoma (most common)
- Malignant melanoma
- Adenocarcinoma (wood dust exposure)
12
Q
***Nasal neoplasms - Lymphoid tumours
A
- Malignant lymphoma
- 2nd most frequent **extranodal lymphoma in Chinese (1st: GI)
- **T cell lineage
- **EBV-associated
- **Polymorphic reticulosis
—> smaller number of ***lymphoma cells intermixed with plasma cells, histiocytes, immunoblasts, neutrophils, eosinophils
—> polymorphous mixture
- Untreated case —> progress into more aggressive conventional lymphoma
- Early biopsy often mistaken for benign lesion ∵ scattered lymphoma cells
—> obtain adequate tissue / repeat biopsy
13
Q
***Nasopharyngeal neoplasms - Nasopharyngeal carcinoma (NPC)
A
- common in southern Chinese
- Males + Middle-aged
- WHO classification:
1. Squamous cell carcinoma (uncommon) ~ those in other parts of oropharynx
2. Differentiated Non-keratinising carcinoma ~ Transitional carcinoma
-
Undifferentiated Non-keratinising carcinoma (most common 95%)
- NO squamous / glandular differentiation (no keratin / gland formation)
- sheets of **polygonal cells / **spindle cells
- **Tumour cells mixed with lymphoid stroma
—> **Lymphoid infiltrate present (prominent)
—> ***Lymphoepithelioma (lymphoid infiltrate which is just local tissue reaction to tumour)
—> ALL have some degree of epithelial differentiation —> derived from same type of cell
14
Q
***NPC Etiology
A
- Genetic factor (modest)
- combination of HLA A2 + BW 46 —> Southern Chinese, not found in Western - Dimethylnitrosamines
- salted fish, phorbol esters in plants / oils —> mutagenic -
**Epstein-Barr virus
- MOST NPCs contain EBV
- patients have elevated serology to EBV: **IgA component of **Viral Capsid Antigen (VCA)
- can **transform epithelial cells into cells capable of cell growth (capable of doing that to lymphoid cells)
- **Additional Diagnostic tests for EBV:
1. In-situ hybridisation
2. Latent Membrane Protein 1 (LMP1) + Bam ARightFragment1 (BARF1) —> Oncogenic proteins produced by EBV
15
Q
Pathogenesis of NPC
A
Normal nasopharyngeal epithelium
—> Reversible mild hyperplasia
—> Early premalignant lesion
—> Irreversible malignant transformation
16
Q
Locations of NPC
A
Nasopharynx
- ***fossa of Rosenmuller (Pharyngeal recess: Opening of Eustachian tube)
- seen as ulcer / nodular area / smooth bulge / fungating mass
- obscure area —> small and clinically silent until widespread metastases
Local spread
- ***Parapharyngeal space —> base of skull —> through foramina —> into Cranium
- local involvement of blood vessel, cranial nerves, lymphatics, muscles
Distal spread
- Lymphatics —> Neck LN in head/neck —> other sites
- Blood —> other organs
17
Q
***Signs and symptoms of NPC
A
- Deafness and Tinnitus
- blockage of Eustachian tube (1st symptom)
- can affect CN8 - Bleeding
- blood in postnasal drip (excess mucus drips to back of throat) (very significant in early diagnosis) - Headache and facial pain
- caused by involvement of CN5
- temporal headache
- ***Corneal reflexes should be tested in suspected patients (involuntary blinking of the eyelids elicited by stimulation of the cornea —> sensory by CN5) - Neck nodes
- 1st palpable nodes: Upper jugular group at apex of ***posterior triangle (back of skull)
- bilateral involvement in 1/3 of case
- can also appear only on contralateral side
18
Q
Treatment of NPC
A
- External radiotherapy
- Undifferentiated carcinoma response best
- SCC least favourable
- Recurrence is high, occur within first 2 years following completion of radiotherapy
—> routine follow up to detect early relapses
—> ***Plasma EBV copy number to determine relapse - Adjuvant chemotherapy
19
Q
Other nasopharyngeal neoplasms / Non-epithelial neoplasms
A
- Sarcoma
- after radiation for NPC - Lymphoma
- T-cell
- associated with EBV
20
Q
Oral cavity and tongue pathologies
A
- Inflammatory
- Aphthous ulcers (飛滋) - Neoplastic
- **SCC (∵ oral mucosa: stratified squamous epithelium)
—> related to **smoking +++
—> other risk: viral (HSV, HPV), poor dentition - Auto-immune
- ***Lichen planus - Traumatic / Toxic
- Ulcers
21
Q
Salivary gland pathologies
A
- Inflammatory
- ***Sialadenitis (inflammation of salivary glands usually ∵ obstruction by stone)
- Mucocele (mucous cyst: obstruction of minor salivary gland by stone) - Neoplastic
- Benign
—> ***Pleomorphic adenoma
—> Warthin’s tumour
- Malignant
—> ***Mucoepidermoid carcinoma
—> Adenoid cystic
—> Lymphoepithelioma-like carcinoma
- Infectious
- Viral: ***Mumps
- Bacteria: uncommon - Auto-immune
- ***Sjögren’s syndrome (destruction of gland —> dry eyes + dry mouth)
22
Q
Benign + Malignant neoplasms of Salivary gland
A
Benign:
- ***Pleomorphic adenoma (most common)
- different appearances within tumour
- Epithelium forming small ducts + Myoepithelial cells
- Stroma: myxoid / chondroid
- Parotid gland
- local excision for treatment: ensure CN7 is preserved
- can get local recurrence - Warthin’s tumour
- Papillary cystadenoma lymphomatosum papilliferum / Adenolymphoma (got lymphoid stroma —> BUT NOT a lymphoma!)
- mostly in Parotid gland
- bilateral
Malignant:
- ***Mucoepidermoid carcinoma (most common)
- combination of Squamous (epidermoid) + Glandular (muco) epithelium - Adenoid cystic
- more common in Minor salivary glands (less in Parotid gland)
- mixture of Myoepithelial cells + Glandular cells
- locally invasive - Lymphoepithelioma-like carcinoma (common in Chinese)
- looks like NPC
- can be associated with EBV
- metastasise to lungs + LN
23
Q
Larynx pathologies
A
- Inflammatory
- **Vocal polyp (singer’s nodule) (most common)
—> chronic laryngitis from mechanical injury to vocal folds (e.g. misuse of voice)
—> Squamous **metaplasia, Localised stromal ***edema, Degeneration - Neoplastic (ALL squamous, Supraglottic / Glottic / Subglottic)
- **Squamous papilloma (most common, associated with HPV)
- Carcinoma-in-situ
- **SCC - Infectious
- Viral (influenza, adenovirus, chicken pox)
- Bacterial (β-haemolytic streptococci, haemophilus influenzae, Corynebacterium diphtheriae) —> Acute laryngitis
- ***Epiglottitis (H. influenzae): severe and rapidly progressive infection in early childhood —> severe oedema involving larynx —> Intubation / Tracheostomy required apart from antibiotic - Congenital
- Laryngeal web: thin and translucent membrane spreading between vocal folds near anterior commissure - Auto-immune
- Bee stings —> oedema - Traumatic / Toxic
- Burns —> oedema
24
Q
Larynx neoplasms
A
Benign
- Squamous papilloma (Juvenile)
- either sex, at very young age
- **multiple lesions covering a wide area of mucosa
- soft, highly mobile (∵ loose / long pedicle)
- high recurrence rate following excision but **disappear after puberty
- may become malignant (usually after repeated irradiations)
- some have viral etiology - Squamous papilloma (Adult)
- **single
- from **vocal folds
- need to distinguish from papillary carcinoma
- rare recurrence
- rare malignant change - Carcinoma-in-situ
- multicentric in origin
- true vocal folds
Malignant
- Invasive SCC
- ~70 years old (any age after childhood)
- history of chronic laryngitis / heavy smoking
- **hoarseness, pain, **dysphagia, ***haemoptysis
25
Q
Anatomical classification of Laryngeal tumours
A
ALL tumours
- ***well-differentiated SCC
- varying degree of keratin formation
- Papillary / Ulcerative / Infiltrative
- direct extension within mucosa, submucosa
-
**Glottic (Vocal folds, Anterior, Posterior commissures)
- most frequent, **better prognosis
- present early with hoarseness
- confined to larynx for some time - Subglottic
- rare, worst prognosis
- metastasise rapidly to regional LN —> Lungs
- may remain silent until advanced stage - Supraglottic
- intermediate
- metastasise rapidly to regional LN —> Lungs
- may remain silent until advanced stage
