13- Epithelial Neoplasia Flashcards
What is the largest organ in the body?
The skin (covers all the external surfaces)
What is the skin made up of ?
The epidermis + dermis
What is the superficial layer of the skin?
Epidermis
What is the supporting fibrous layer of the skin?
The dermis?
What is in-between the dermis & epidermis?
The basement membrane
What lines the cavities connecting the outside of the body?
The mucous membrane (mucosa)
What are the 3 types of tracts that line the body?
1.) Genitourinary tract
2.) Respiratory tract
3.) Gastrointestinal tract
What is the mucosa composed of?
Epithelium (surface layer) + lamina propria (supporting fibrous layer)
T or F, the epithelium is vascular.
False, it is avascular & no blood vessels are feeding into this tissue
How is the epithelium of the mucosa characterized by?
By the the presence of cytokeratin
What cell populations are chracterized as a stratified squamous epithelium?
1.) Epithelial cells
2.) Melanocytes
3.) Langerhans cells
4.) Merkel cell (not discussed in this lecture)
What are the keratinizing epithelial cells called in the epithelium?
Keratinocytes
What are the layers of the epithelium (from top to bottom)
1.) Stratum corneum
2.) Stratum lucidum
3.) Stratum granulosum
4.) Stratum spinosum
5.) Stratum basale
Where are melanocytes found in the epithelium?
In between cells in the basal layer.
How do melanocytes function in the epithelium?
They are the cells that account for different pigmentation in humans.
What can stimulate the melanocytes to produce more melanin?
Sunlight can result in this.
What are the Langerhans cells in our epithelium?
They act as an antigen presenting cells (aka dendritic cells) which have a major role in the immune response involving the epithelium
T or F Langerhans cells are dendritic cells?
True
T or F, Langerhans cells are phagocytic & part of MHC Class I molecules.
False, they are phagocytic but are part of the MHC Class II molecules.
What are the 3 oral mucosal division?
1.) The lining mucosa
2.) Masticatory mucosa
3.) Specialized mucosa
How can we characterize the lining mucosa?
- For flexibility
- for reduction of surface toughness
- Non-keratinized
e.g: buccal mucosa
Floor of mouth
How can we characterize the masticatory mucosa?
- For resistance to frictional forces
- For well-keratinized
- Minimal flexibility
e.g: Gingiva
hard palate
How can we characterize the specialized mucosa?
- Complex surface allowing support of the taste buds.
- Allows to maximize flexibility while still resisting masticatory forces.
What are neoplasms?
A single cell which may exhibit clonal growth. They can either benign or malignant. Where the cell has changed to grow/proliferate on its own & does NOT respond to stimuli normally anymore
What is defined as anaplasia?
When neoplastic cells are poorly differentiated that it is difficult or impossible to determine morphologically, the tissue of origin.
What is defined as benign?
- Neoplasms in which cells do not metastasize
- These neoplasms that can still cause local damage
- Generally exhibit a good prognosis
What is defined as differentiation? `
In the topic of neoplasm, it is when the neoplastic cell can either have similarities to its parent cell or not.
When a neoplasm is “well differentiated” what that does imply?
That the neoplastic cell looks like the parent cell (generally better prognosis)
When a neoplasm is “poorly differentiated” what does that imply?
That the neoplasm cell does NOT resemble the parent cell (generally worse prognosis)
What is epithelial dysplasia?
It is the histologic alterations of the epithelial cells.
Correlates to the increased potential of malignancy.
What are the 3 degrees of dysplasia?
Mild
Moderate
Severe
Which of the 3 degrees of dysplasia has the best prognosis?
Mild
Which of the 3 degrees of dysplasia has the worst prognosis?
Severe
What does malignant mean?
This is a neoplasm with the potential for metastasis + generally more aggressive & associated with morbidity.
What is metastasis?
To detach neoplastic sites from original growth & migration to other sites.
What are examples of tumours that can be metstasize?
- Lymphatic
- Vasculature
- Direct extension
What is commonly mestasizes via lymphatics?
Oral squamous cell carcinoma (OSCC). (which is why neck palpitation is a critical component
What is neoplasms?
They are considered as the “new grow” in neoplasms which does not respond normally to regular mechanisms.
What is oncology?
It is the study of neoplasms
What are the 4 models of carcinogenesis that influence genetic damage?
1.) Time
2.) External agents/spontaneous mutations
3.) The targeting of oncogenes
4.) Unrestrained clonal proliferation.
What is carcinogenesis?
The development of cancer due to damage to particular genes.
What are the two major types of genes in carcinogenesis?
1.) Tumour suppressor genes
2.) Oncogenes
What are tumour suppressor genes?
They are the genes that protect cells from cancerous change.
What occurs when tumour suppressor genes are destroyed by carcinogens + mutations?
The cells begin to proliferate & which can lead to cancer
How can changes in a tumor suppressor gene become evident?
When it undergoes mutations.
What are oncogenes?
They are genes that have the potential to cause cancerous changes.
What would occur if oncogenes are damaged + mutated?
Their expression can increase & may lead to cancer.
What is a carcinogen?
It is a cancer-causing agent which can cause genetic mutations & lead to the development of cancer.
What are some example of carcinogens?
1.) Tobacco smoke
2.) UV radiation
3.) Chemicals: arsenic, asbestos, benzene
4.) Viruses
5.) Alcohol
What is described as the nuclear hyperchromatism?
1.) Excessive nuclear staining
2.) Intensely dark appearance of the nucleus
What is described within a nuclear + cellular pleomorphism?
Variable size of the cell & nucleus.
What are histologic features of a malignant cells?
1.) Nuclear staining
2.) Size of cell + nucleus
3.) Ratio of the nucleus cytoplasm
4.) The increase + normality of the mitotic figures
When grading a type of cancer, what kind of determination are we concluding? what does it represent?
It is a HISTOPATHOLOGIC determination, it represents the degree to which the cells are differentiated.
(essentially differentiating the levels of dysplasia of a cell through a microscope)
When scaling a type of cancer, what would be the basis scale of measurement used to describe the cell?
A TNM scale would be used to make a clinical decision to describe how far a tumor has spread.
What does TNM stand for when scaling a particular tumor?
Tumour, Nodes & Metastasis
T or F, Staging is the most important level of measurement over grading cancer to determine the patient’s prognosis.
True, Staging is MORE important than grading.
What is a neoplasm named according to ?
It is named according to its tissue of origin.
What would be the indication of a benign tumour?
If it has a suffix “oma” attached to its name.
Prefix would indicate the tissue of origin.
e.g:
- Fibrous tissue = fibroma
- Bone = Osteoma
- Cartilage = chondroma
What would be the indication of a malignant tumour?
if the tumour is grouped in to one of three main categories:
1.) epithelial = Carcinoma
2.) Mesenchymal = Sarcoma
3.) Hematopoetic = Lymphoma, leukemia
What is an example of malignant tumour in the bone?
Osteosarcoma
What is an example of a malignant tumour in the cartilage?
Chondrosarcoma
What is an example of a malignant tumour in the fibrous tissue?
Fibrosarcoma
What is an example of a malignant tumour in the fat?
Liposarcoma
What is an example of a malignant tumour in the blood vessel?
Hemangiosarcoma
What is an example of a malignant tumor in the muscles?
Rhabdomyosarcoma (skeletal)
Leiomyosarcoma (smooth muscle)
What is an example of a malignant tumour in the lining of the epithelium?
Squamous cell carcinoma
What is an example of a malignant tumor in the glandular epithelium?
Adenocarcinoma
What is an example of a malignant tumor in the melanocytes?
Melanoma
What are 90% of the causes of all oral cancers?
Squamous cell carcinoma
What 3 factors would encourage oral cancers in individuals?
1.) Age: 95% in pts over 40 yrs old
2.) Gender: in Males (changed due to smoking habits)
3.) Site: on the lower lip, lateral & ventral tongue + floor of the mouth.
What are the etiologies that may cause oral cancers?
1.) Multifactorial causes: extrinsic + intrinsic factors
2.) Multi-step process
3.) Tobacco smoking/chewing: smoking>smokeless tobacco + dose & duration dependent
4.) Alcohol abuse
other causes:
5.) Sunlight/UV exposure
6.) General malnutrition
7.) Immunodeficiency
8.) Lichen planus
9.) Iron-deficiency anemia: Plummer Vinson Syndrome
10.) HPV
11.) Oral submucous fibrosis
What is Plummer Vinson syndrome? & who is it most prevalent to?
It is an oral cancer related to iron-deficiency (anemia). It is most prevalent to middle aged women.
What are the symptoms of Plummer Vinson Syndrome?
1.) Dysphagia
2.) Esophageal webbing
3.) Iron deficiency anemia
4.) Increased risk of oral cancer
5.) Nail changes.
HPV 16 & 18 are cancers associated to what region of the body?
The head & neck region.
*Now closely related with an oropharyngeal cancer, which is anatomically different than oral cancer
What is an oral submucous fibrosis?
It is a stiffening of the oral mucosa due to the use of betel quid (increases risk of oral cancer)
In what kind of individuals is oral submucous fibrosis typically seen in?
Primarily seen in East Indian populations.
How is nicotine stomatitis described as?
Described as a thickened white appearance, with punctate red lesions on the palate
How can nicotine stomatitis appear as an oral cancer?
Due to smoking: from the heat of smoking. (NOT considered malignant)
How can nicotine stomatitis be treated?
With 1-3 months of smoking cessation.
What are some limitations to an oral cancer examination?
The visualization of the oropharynx completely.
What are the 3 questions we want to ask if we see a lesion?
1.) If the patient has been placing anything in their mouth
2.) If the patient attempted to treat the area
3.) If the area has been getting better or getting worse?
What are some of the clinical presentations of oral cancer?
1.) Ulcerations
2.) Mass
3.) White or red/white plaque
Clinical features of leukoplakia can be seen in what color of lesions/plaques?
White lesions/plaques
Clinical features of erythroplakia can be seen in what color of lesions/plaques?
Red lesions/plaques
What are examples of which oral cancers can appear in local metastasis?
Cervical lymph nodes
What are examples of which oral cancers can appear in distant metastasis?
Lungs, liver, bones
Can erythroplakia & leukoplakia represent as an oral cancer? why or why not?
Not necessarily as they are known as an oral potentially malignant disorders (PMDs)
- Represent an elevated risk of oral cancer & as such are clinically important.
How can an erythroplakia be described as?
A red mucosal patch that cannot be diagnosed as any other specific pathologic condition.
*biopsy is mandatory
* generally show malignancy or premalignant changes on biopsy: 90% will show dysplasia or cancer on biopsy
What symptom is most directly related to an erythroplakia when discussing potential oral cancers?
The thinning of the red-coloured tissue due to the disordered epithelial maturation. (dysplasia + squamous cell carcinoma)
How can a leukoplakia be described as?
A white mucosal patch cannot be diagnosed as any other specific pathologic condition.
*A biopsy must be performed to obtain definitive diagnosis
What can a biopsy of a leukoplakia lesion tell us?
It can show us the variable histology ranging from squamous cell carcinoma (cancer) to hyper keratosis (a callus)
What symptom is most directly related to a leukoplakia when discussing potential oral cancers?
The increased thickness of epithelium secondary to disordered epithelial maturation. (dysplasia + squamous cell carcinoma)
What is proliferative verrucous leukoplakia?
It is a specific type of leukoplakia found in older women without the traditional risk factors of smoking or alcohol
*High risk of leukoplakia
*has the verrucous appearance
*poor prognosis
What is the hallmark of oral squamous cell carcinoma?
The invasion of epithelium into underlying connective tissue.
What would affect the prognosis of oral cancers? staging or grading?
Staging would affect the prognosis
What are diagnostic adjuncts?
They are commercially available tools used by dental professionals to aid in the diagnosis of oral cancers & other intraoral pathologies.
What are some examples of diagnostic adjuncts available for dental professionals?
1.) Autofluorescence (VELscope)
2.) Tissue reflectance (ViziLite)
3.) Vital staining (Toluidine blue)
4.) Cytologic testing (OralCDx)
When would be an appropriate time to utilize a diagnostic adjuncts?
For patients with evident mucosal lesion, biopsy or referral to a specialist is indicated
When would a biopsy be recommended?
When there is any positive or atypical result reinforcing the need for biopsy.
*Negative results would indicate requirement for follow-up.
What are the 3 diagnostic adjuncts that are NOT recommended for the evaluation of potentially cancerous lesions?
1.) Autofluorescence
2.) Tissue reflectance
3.) Vital staining
How is oral cancer generally treated by?
By surgery or radiation (or even both)
What is typically the first option for oral cancer?
Performing a surgery
What is typically used for treatments of oropharyngeal carcinomas?
Radiation + chemotherapy
At what stage are oral cancers commonly diagnosed at?
Not until the advanced stage (>2cm)
What does the TNM staging system include?
T- tumor size
N - involvement of lymph nodes
M - metastatic diseases
What is the survival rate of a patient undergoing Stage 1-4 cancers?
1- 72%
2- 58%
3- 45%
4- 32%
What is a papilloma?
It is a benign “cauliflower-like” proliferation of squamous epithelium.
*benign counterpart of squamous cell carcinoma
What is the etiology a Papilloma?
From HPV infections (HPV 6 & HPV 11) are the most common.
What kind of cancers are HPV 16 & HPV 18 correlated to?
Oropharyngeal cancers
Where can we typically find the papilloma?
On the tongue, lip & soft palate
What kind of appearance does a papilloma exhibit?
- A verrucous appearance + classic papillary
Is papilloma contagious?
No it is not, though it is transmissible.
What are the treatments needed for a Papilloma?
1.) Surgical excision
* NO laser, as it can be in the laser plume
What is a verruca vulgaris?
It is a virally induced epithelial lesion. It is most commonly known as a wart, typically found on the skin.
Are verruca vulgaris’ contagious?
They are indeed very contagious.
What is a condyloma acuminatum? what infection is it associated with?
It is a sexually transmitted infection associated with HPV 6, 11, 16 & 18
What is a multifocal epithelial hyperplasia? In what population is this commonly seen in?
They are known as the virally induced proliferation of the epithelium. They are most commonly seen in indigenous/Inuit populations.
What is the etiology of multifocal epithelial hyperplasia?
In HPV 13 & 32
How do multifocal epithelial hyperplasias appear as? & where are they commonly seen?
They appear as clusters of lesions & most commonly seen on the labial + buccal gingiva
What are the treatments performed for a multifocal epithelial hyperplasia?
1.) Spontaneous regression
2.) Surgical excision
What are verruciform xanthomas?
They are focal papillary lesions of unknown origin. they are NOT related to HPV.
Where are verruciform xanthomas commonly located in?
In the gingiva (most common area)
What treatment is needed to cure verruciform xanthoma?
A surgical excision.
