Post on 04-Apr-2018
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Oral Pathologyfor the DentalHygienist
Chapter 7-Neoplasia
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Neoplasia Description
Neoplasia= New growth. It is a process in
which cells exhibit uncontrolled proliferation.
Neoplasm- is a mass of cells.
Ex. Tumor is a commonly used synonym for
neoplasm
Oncology- study of tumors
Neoplasia is an abnormal process, cells areabnormal, and the proliferation of these cells
is uncontrolled and unlimited
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CAUSE OF NEOPLASIA
Chemicals mainly, viruses and radiationhave been shown to cause neoplastic
transformation of cells Radiation from sunlight, x-rays, nuclear
fission, or other sources are wellestablished as cancer-producing agentsin humans
Viruses that cause tumors are oncogenicviruses
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CLASSIFICATION OF TUMORS
2 categories: Benign & Malignant
Benign tumor- remains localized, can be
encapsulated (walled off by surroundingfibrous connective tissue), can not spreadto distant sites, normal cells
Malignant tumor- invades and destroyssurrounding tissue and has the ability tospread throughout the body.Compromised of neoplastic cells
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MALIGNANT
Well-differentiated tumors, but can alsobe poorly differentiated
Have only some characteristics of thetissue which they were derived
Pleomorphic- vary in size
Nuclei darker than normal
(hyperchromatic)Composed of cells that vary in size and
shape (pleomorphic)
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Names of Tumors-Benign
Prefix of the name of the tumor isdetermined by the tissue or cell of origin
Suffix oma- used to indicate a tumor
Ex. Lipoma= benign tumor of fat
Osteoma= benign tumor of bone
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Names of Tumors- Malignant
Malignant tumors prefix is also determinedby the tissue or cell of origin
Ex. Malignant tumors of epithelium =carcinoma
Malignant tumors of connective tissue=sarcoma
Malignant tumor of squamous epithelium=squamous cell carcinoma
Malignant tumor of bone= osteosarcoma
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Treatment of Tumors
Benign- generally treated by surgicalexcision either by local excision or
enucleation
Malignant- treated by surgery,chemotherapy, or radiation therapy, acombination is often used
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Figure 7-1
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Epithelial Tumors
3 different types
1.tumors derived from squamousepithelium
2. tumors derived from salivary glandepithelium
3. tumors derived from odontogenicepithelium
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Tumors of SquamousEpithelium
Papilloma- benign tumor of squamousepithelium that presents as a small, exophytic,
pedunculated or sessile Tumors are composed of numerous papillary
projections, can be white or the color ofnormal mucosa
Often described as cauliflower like
Most cases on soft palate or tongue Treated by surgical excision , and must
include the base of the growth
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Figure 7-2 papilloma
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Premalignant Lesions-Leukoplakia
Clinical term and does not refer to aspecific histologic appearance
Defined as white palquelike lesion of theoral mucosa that cant re rubbed off andcant be diagnosed as a specific disease
Most leukoplakias are the result of
hyperkeartosis or a combination ofepithelial hyperplasia
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Figure 7-3 Leukoplakia
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Figure 7-4 tobacco pouchkeratosis
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Leukoplakia continued
Leukoplakia may also show epithelialdysplasia, a premalignant condition, or
even squamous cell carcinoma, amalignant tumor of squamous epithelium
studies have shown that leukoplakiafound on floor of mouth, ventrolateral
tongue, and lip is more likely to beepithelial dysplasia or squamous cellcarcinoma than leukoplakia
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Leukoplakia continued When a white lesion is identified in the oral
cavity.
First goal is to identify the cause If lesion does not resolve a biopsy and histologic
exam must be performed
Any white lesion that is found as epithelialdysplasia or that cant be diagnosed as a specificdisease should be completely removed.
When leukoplakia is found on floor of mouth,ventrolateral tongue, or lip, the lesion should beremoved regardless of the histologic appearance
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Erythroplakia
Oral mucosal lesion that appears as asmooth red patch or a granular red
velvety patch
Lesion that shows a mix of red and whiteareas is called speckled leukoplakia
Can occur in the floor of the mouth,
tongue, and soft palate.
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Epithelial Dysplasia
Disordered growth
Considered a premalignant condition.
Cellular changes may revert to normal ifstimulus such as tobacco is removed
Presents clinically as an erythematouslesion (erythroplakia), white lesion
(leukoplakia), or a mixed erythematousand white lesion (speckled leukoplakia)
Often in floor of the mouth
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Figure 7-5 epithelial dysplasia
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Squamous Cell Carcinoma Malignant tumor of squamous epithelium
Most common primary malignancy of the oralcavity
Usually mestasizes to the lymph nodes of theneck and then to lungs and liver
Clinically presents as exophytic ulcerativemass
Early presents as erythematous and
plaquelike (erythroplakia), white andplaquelike ( leukoplakia), or a mix (speckledleukoplakia)
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Squamous cell Carcinomacontinued
It can occur anywhere in the oral cavity,but most tumors are on the floor of the
mouth, ventrlateral tongue, soft palate,tonsillar pillar, and retromolar areas
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Figure 7-6 multiple places that squamous cell carcinoma
appears
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Squamous cell carcinomacont.
May occur on vermilion border of lips andskin of face
Much better prognosis than in the oralcavity
Solar or actinic cheilitis- mild to severepithelial dysplasia occurs from sun
damage
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Risk factors-squamous cellcarcinoma
Tobcaao most significant (cigar,pipe,cigatette, snuff/chewing tobacco)
Alcohol
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Treatment and Prognosis