Oral Pathology Flashcards
Where are squamous cell carcinomas of the tongue most common?
On the lateral border of the tongue and the floor of the mouth.
What are squamous cell carcinomas of the tongue associated with?
They are aggressive tumours associated with other co-morbidity
What is a cyst?
A pathological cavity filled with fluid (gaseous or semi-fluid but not created by pus accumulation) and is lined by epithelium
What are the clinical features of a cyst?
Noticeable swelling Discharge into the mouth Pain due to secondary infection
How are cysts diagosed?
Combination of adequate history, clinical examination, and selected investigation (radiographs)
How are cysts classified?
They are either epithelial or non-epithelial.
What are non-epithelial cysts also known as?
Pseudocysts (eg. solitay bone cyst and aneurysmal)
What are the types of epithelial cysts?
Odontogenic Non-odontogenic
What are the types of non-Odontogenic cysts? What causes non-odontogenic cysts?
Nasopalatine duct cysts Nasolabial There are related to developmental defects
What are the the types of odontogenic cysts?
Inflammatory Developmental
What is another name for inflammatory odontogenic cysts?
Radicular cysts (Can be apical, lateral, or residual) Paradental cysts
Where do radicular inflammatory cysts appear?
Close to apex of root of the tooth (apical) Side of the root of the tooth (Lateral) When tooth is extracted the lesion is residual. (residual)
What are paradental cysts?
A group of inflammatory odontogenic epithelial cysts.
What are the subtypes of developmental cysts?
Dentigerous Odontogenic keratocyst Lateral periodontal Gingival - infants Gingival - adults Eruption cyst (cyst that interrupts eruption of the tooth)
What is a potential consequence of odontogenic keratocysts?
Can cause large amount of destruction to mandible or maxillary bone.
What percentage of all jaw cysts are radicular cysts?
60 - 75% (Most common)
What ages are radicular cysts most commonly seen in?
Peak in 4th adn 5th decades of life.
What are radicular cysts commonly seen in?
It is associated with non-vital tooth (Dead teeth where hard tissue is alive but soft tissue has died often due to necrotic bulb within tooth) Most common tooth it is seen in is upper lateral incisor.
What teeth are radicular cysts rare in?
It is rare in deciduous teeth.
What do the progression of symptoms look like in radicular cysts?
Asymptomatic or expansion -> springy -> egg-shell crackling -> fluctuation Usually these cysts are asymptomatic until they are infected.
Types of radicular cysts:
Apical where the cyst is located at the root of the tooth.
Lateral where the cyst is directly lateral to the root of the tooth
Residual where the cyst is located in the socket of the tooth that has been pulled out.
What radiological methods can be implemented for diagnosis of radicular cyst?
X-ray
How are radicular cysts treated?
They must be removed. They can be destructive to teeth if not fixed.
How are radicular cysts diagnosed?
Soft tissue biopsy
X-ray
What would a biopsy of radicular cysts show?
Cholesterol crystals
Serum proteins
Water and electrolytes
Breakdown of cell products
What tissue lines a radicular cyst?
Non-keratinised stratified squamous epithelium (diagnostic feature)
Foam cells, lymphocytes, plasma cells, cholesterol clefts, and surrounding fibrosis.
Lining becomes thinner and less inflamed.
What are odontogenic keratocysts known as now? Why?
Odontogenic keratocystic tumours because they are very aggressive and they are associated with genetic mutations.
What percentage of jaw cysts are odontogenic keratocysts?
5 - 10% of all jaw cysts
Where on the jaw do odontogenic keratocysts most commonly present?
70 - 80% on mandible
50% on the angle/ramus
What are the symptoms of odontogenic keratocysts?
Often asymptomatic (unless there is a concurrent infection)
Swelling
Discharge
Pain
Pathological fracture
Tooth displacement
Rarely buccal expansion
True or False;
Odontogenic keratocysts have a high recurrance rate.
True
What does a odontogenic keratocyst look like radiologically?
Well demarcated radiolucency
Pseudolocular or multilocular often with scalloped periphery
Root or tooth displacement
How are ameloblastomas treated?
It required excision of the entire area of the mandible.
What does histologic evaluation of ameloblastoma looke like?
Reverse polarity (nucleus on the opposite side) is the main characteristic feature of ameloblastoma.
What is leukoplakia?
White ulcerated lesion that is an OPMD with 0 - 34% chance of malignant transformation.
What is erythroplakia?
Very rare red OPMD lesion which has a 90% change of becoming cancer.
What kind of architecture changes are observed for chances of OPMD conversion into malignancy?
Irregular epithelial stratification
Loss of polarity of basal cells
Drop-shaped rete ridges
Increased number of mitotic figures
Abnormally superficial mitoses
Premature keratinisation in single cells
Keratine pearls within rete ridges
What kind of cytology changes are observed for chances of OPMD conversion into malignancy?
Abnormal variation in nuclear size and shape
Abnormal variation in cell size and shape
Increase Nuclear-cytoplasmic ratio
Increase in nuclear size
Atypical mitoses
Increase number and size of nucleoli
Hyperchromatism
What does histology tell us about the severity of basal cell carcinoma?
Lower third is considered mild
Lower 2/3rds is considered moderate
If it extends to full thickness it is called full carcinoma
What does severe dysplasia/carcinoma in situ look like?
Mitotic divisions everywhere with random cell sizes as well as drop shaped rete ridges.
The reason it is called carcinoma in situ is because there is no ridge for the basement membrane so it can grow very quickly.
