HISTOPATOLOGI TUMOR-TUMOR GANAS

RONGGA MULUT

Diana Nurwati, drg., M.S.

TUMOR GANAS EPITEL

Squamous papilloma

• The squamous papilloma is a benign proliferation of stratified squamous epithelium, resulting in a papillary or verruciform mass.

Histopathologic Features

• The papilloma is characterized by a proliferation of keratinized stratified squamous epithelium arrayed in finger like projections with fibrovascular connective tissue cores.

• The connective tissue cores may show inflammatory changes, depending on the amount of trauma sustained by the lesion.

• The keratin layer is thickened in lesions with a whiter clinical appearance, and the epithelium typically shows a normal maturation pattern.

• Occasional papillomas demonstrate basilar hiperplasia and mitotic activity, which can be mistaken for mild epithelial dysplasia.

Squamous papilloma. Low power view showing a pedunculated squamous epithalial proliferation. There are multiple papillary projections with fibrovascular connective tissue cores Squamous papilloma. The tip of a papillary

projection shows mature stratified squamous epithelium with a slightly thickened parakeratin surface layer

Squamouse Cell Carcinoma

Histopathologic Features

• Squamous cell carcinoma arises from dysplastic surface epithelium and is characterized histopathologically by invasive islands and cords of malignant squamous epithelial cells.

Well differentiated squamous cell carcinoma. Low-power photomicrograph showing islands of malignant squamous epithelium invading into the lamina propria

Well differentiated squamous cell carcinoma. High-power view showing dysplastic epithelial cells with keratin pearl formation.

Basal cell carcinoma (basal cell epithelioma; rodent ulcer)

Histopathologic Features

• The cells are arranged into well-demarcated islands and strands, which appear to arise from the basal cell layer of the overlying epidermis and invade into the underlying dermal connective tissue.

• Epithelial islands typically demonstrate palisading of the peripheral cells.

Basal cell carcinoma. Low power photomicrograph showing ulceration of the epidermal surface associated with invading tumor of hyperchromatic epithelial cells. Inset demonstrates islands of basophilic epithelium with periperal palisading

Melanoma (malignant melanoma; melanocarcinoma)

Histopathologic Features• Cutaneous and oral melanomas, atypical melanocytes

are initially seen at epithelial and connective tissue junction.

• From here, they have the potential to proliferate throughout the epithelium, laterally along the basal cell layer, and downward into the connective tissue.

• In the early stages of the neoplasm, atypical melanocytes are seen either scattered singly among the basal epithelial cells or as nests within the basal cell layer.

• The atypical melanocytes are usually larger than normal melanocytes and have varying degrees of nuclear pleomorphism and hyperchromatism.

Acral lentiginous melanoma. This palatal melanoma demonstrates numerous atypical melanocytes in the basilar portion of the epithelium with invasion into the superficial lamina propria.

LESI PRA GANAS

Acquired melanocytic nevus (nevocellular nevus; mole)

• The generic term nevus refers to malformations of the skin (and mucosa) that are congenital or developmental in nature. Nevi may arise from the surface epithelium or any of variety of underlying connective tissues.

Histopathologic features

• Nevus cells are found only along the basal cell layer of the epithelium, especially at the tips of the rete ridges.

• Because the lesional cells are found at junction between the epithelium and the connetive tissue, this stage is known as a junctional nevus.

• The nevus cells proliferate, groups of cells begin to drop off into the underlying dermis or lamina propria.

• Because cells are now present both along the junctional area and within the underlying connetive tissue, the lesion then is called a compound nevus.

• In the later stages, nests of nevus cells are no longer found within the epithelium but are found only within the underlying connective tissue.

• Because of the connective tissue location of the lesional cells, on the skin this stage is called an intradermal nevus.

• The intra oral counterpart is called an intramucosal nevus.

Junctional nevus. Nests of melanocytic nevus cells along the basal layer of the epithelium

Compound nevus. High power view showing nests of pigmented nevus cells within the epithelium and the superficial lamina propria

Intradermal nevus. Collections of melanocytic nevus cells only within dermis