NEOPLASMA JINAK

KULITDEPARTEMEN PATOLOGI ANATOMI

FAKULTAS KEDOKTERANUMI - UHN

Structure of the Skin

NEOPLASMA OF THE SKIN

caused by papillomavirus transmitted from one site to another—and one

person to another—by direct contact. the fingers are the most common single site.

Histologically : The wart is a squamous papilloma with variable

keratinization and conspicuous keratohyaline granules.

Large vacuolated cells in the proliferating squamous epithelium stain positively for papilloma virus by the immunoperoxidase technique.

Verruca Vulgaris (Common Wart)

Caused by virus of the poxvirus group. Lesions consist of small and discrete dome-

shaped papules that have an umbilicated center.

Heal spontaneously. Histologically : The epidermis bulges downward into the

dermis and the epidermal cells contain intracytoplasmic inclusion bodies molluscum bodies.

Molluscum Contagiosum

Very common lesion. Occurring on the trunk, extremities and face. Usually in elderly persons. Lesions are flat, raised, soft, sharply

demarcated, and brown. Seborrheic keratosis is benign and probably not

a true neoplasm. Histologically : Seborrheic keratosis is a flat,

often pigmented squamous epithelial proliferation with many keratin-filled cysts (horn cysts).

Seborrheic Keratosis

Occurs in middle age. Commonly on the face or upper extremities. Characterized by a rapid early growth

phase, reaching maximum size in a few weeks, followed by a static phase (up to 1 year) after which the lesion spontaneously involutes with scarring.

Keratoacanthoma

Histologically : keratoacanthoma appears as a cup-shaped

lesion with an irregular keratin-filled crater in the center.

Though resembling invasion, the base of the lesion is smooth and does not penetrate deeper than the level of the hair follicles.

The cells frequently show mild atypia, mitotic activity, and dyskeratosis, making histologic distinction from squamous carcinoma difficult.

Keratoacanthoma… continue

The term nevus (Latin naevus, mole) is used in a general sense for many cutaneous lesions present at birth.

Melanocytic nevi are usually not present at birth but appear in childhood and stop growing soon after puberty.

They are benign and present clinically as flat, papular, papillomatous or pedunculated pigmented (black or brown) lesions.

If a nevus changes its form in any way, malignancy should be suspected.

Nevocellular Nevus (Melanocytic Nevus)

Histologically : Moles are composed of nests of nevus

(melanocytic) cells, which may be found in the dermis (intradermal nevus),

at the junction between epidermis and dermis (junctional nevus),

in both locations (compound nevus).

Nevocellular Nevus (Melanocytic Nevus)

Junctional activity (melanocytic proliferation in the junctional zone) usually decreases after puberty.

If it is prominent in an older patient or associated with cytologic atypia, malignant melanoma should be considered.

In young patients, compound nevi may show marked cytologic atypia, pleomorphism, and junctional proliferation (Spitz nevus) with no implication of malignant behavior.

Nevocellular Nevus (Melanocytic Nevus)