Beningn epithelial tumors ii/certified fixed orthodontic courses by Indian dental academy

www.indiandentalacademy.com

BENIGN TUMORS OF THE EPITHELIAL TISSUE ORIGIN II

INDIAN DENTAL ACADEMYLeader in continuing Dental Education


OBJECTIVES

At the end of the lecture student should be able to

• Describe classification, incidence, etiology, clinical features histopathological features of nevus.


PIGMENTED CELLULAR NEVUS(pigmented mole, benign melanotic nevus)

DEFINITION• defined as a congenital, developmental tumor- like

malformation of the skin or the mucous membrane

CLASSIFICATION• Intradermal nevus (common mole)• Junctional nevus • Compound nevus • Spindle cell &/ or epitheloid cell nevus • Blue nevus


Clinical features • Congenital nevus- small or garment nevi• Small- 3-5 cms • Large- 10 cms• Congenital seen in 1-2.5% in neonates

-Intraoral occurrence rare

• Acquired nevus- common• 8th mnth of life increases with age• Increases in no. with age• Peak in late third decade of life

• Intra dermal nevus-several/ dozens scattered over the body-smooth flat lesion or may be elevated -may/may not exhibit brown pigmentation-strands of hair growing from the surface

Melanocytes


• Junctional nevus -similar to intradermal nevus-distinctly diff histologically

• Compound nevus-composed of intradermal nevus & overlying junctional nevus Pigmented nevus cells



Spindle cell/ epitheloid cell nevus

-in children

-similar to malignant melanoma

-clinically benign but histologically malignant


Blue nevus

-true mesodermal composed of dermal melanocytes-rarely malignant change-occurs on buttocks, dorsum of feet & hands-present at birth & persists-smooth & hair grows from its surface -brown – blue / bluish- black


• Oral manifestations-hard palate, buccal mucosa, lip & gingiva-raised pigmented areas

• Histological features-large discrete cells, ovoid vesicular nucleus & pale cytoplasm -sheets or cords may contain granules of melanin in their cytoplasm-arrangement of cells in theques


• Intradermal nevus -nevus in the CT is seperated from the epith by definite band of connective tissue -nevus cells not in contact with epithelium


-

zone of demarcation absent -nevus cells blend with the epithelium

-overlying epithelium- thin & irregular & crosses the junction giving a dropping or abtropfung effect

-Tendency to undergo transformation into malignant melanoma.

Junctional nevus

Compound nevus

• -Shows features of both junctional and intradermal nevus. -nests of nevus cells & dropping off from the epidermis-large nest present in the dermis

• Blue nevus

-common/cellular blue nevus



-common- large melanocytes with large dendritic processes parallel to epidermis-no junctional activity

-cellular – large round or spindle cell with pale vacuolated cytoplasm-cells arranged in an alveolar pattern

TreatmentSurgical excision

Melanin pigment


Summary • Classification• Incidence• etiology• Clinical features• Histological features of nevus.



THANK YOU !