Chapter 7 Path

7/29/2019 Chapter 7 Path

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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

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