skin tumors word

Skin tumoursد.وسام اللامي

Benign epidermal tumors
Seborrhoeic keratosis
This is a common benign epidermal tumour, un-related to sebaceous glands.
sudden eruption of hundreds of itchy lesions is associated with an internal neoplasm ( Leser–Trélat sign ). Usually arise after the age of 50 years. They are often multiple but may be single. Lesions are most common on the face and trunk. The sexes are equally affected.
On examination, distinctive ‘stuck-on’ appearance. May be flat, raised, filiform or pedunculated. Surface may be smooth or verrucous. Colour varies from yellow–white to dark brown–black. Seborrhoeic keratoses can safely be left alone, but ugly or easily traumatized ones can be removed with a curette under local anaesthetic, or by cryotherapy.
Skin tags (acrochordon)
These common benign outgrowths of skin affect mainly the middle-aged and elderly.Cause unknown, sometimes familial. Skin tags are most common in obese women, and rarely are associated acromegaly and diabetes. Occur around the neck and within the major flexures. They look unsightly and may catch on clothing and jewellery. They are soft skin-coloured or pigmented pedunculated papules. Tags may confused with small melanocytic naevi. Small lesions can be snipped off with fine scissors, frozen with liquid nitrogen or destroyed with electrodessication without local anaesthesia.
Naevi
Naevus refers to a skin lesion that has a localized excess of one or more types of cell in a normal cell site. Naevi may be composed mostly of keratinocytes (epidermal naevi), melanocytes (congenital melanocytic naevi), connective tissue elements (connective tissue naevi) or a mixture of epithelial and connective tissue elements (sebaceous naevi).

Linear epidermal naevus tends to follow Blaschko’s lines. Keratinocytes in these lines appear as wart-like growth. Keratolytics lessen the roughness of some and small epidermal naevi may be excised.
Melanocytic naevi Moles are localized benign tumours of melanocytes.The cause is unknown. A genetic factor working together with excessive sun exposure during childhood. New melanocytic naevi appear less often after the age of 20 years. Melanocytic naevi in childhood are usually of the‘junctional’ type, with proliferating melanocytes in clumps at the dermo-epidermal junction. Later, the melanocytes round off and ‘drop’ into the dermis. A ‘compound’ naevus has both dermal and junctional components. With maturation the junctional component disappears so that the melanocytes in an‘intradermal’ naevus are all in the dermis.
Spitz naevi They develop over a month or two as solitary pink or red nodules up to 1 cm in diameter, common on the face and legs. Benign, excision is best.
Blue naevi So-called because of their striking grey–blue color, appear on the limbs, buttocks and lower back. usually solitary.
Mongolian spots Pigment in dermal melanocytes is responsible for these bruise-like greyish areas seen on the lumbosacral area of most Down’s syndrome and many Asian and black babies. They usually fade during childhood.
Sebaceous naevus A flat hairless area at birth, usually in the scalp, these naevi become more yellow and more raised at puberty. Risk of development of basal cell carcinomas in adult life.
Malignant change should be considered if the following changes occur in a melanocytic naevus: Enlargement, increased or decreased pigmentation, altered shape, altered contour, inflammation, ulceration, itch, or bleeding. Excision is needed when:a naevus is unsightly; malignancy is suspected or is a known risk as large congenital melanocytic naevus a naevus is repeatedly inflamed or traumatized.


Epidermoid and pilar cysts
Common and can occur on the scalp, face, behind the ears and on the trunk. They often have a central punctum; when they rupture or are squeezed, foul-smelling cheesy material comes out. The lining of a cyst resembles normal epidermis (an epidermoid cyst) or the outer root sheath of the hair follicle (a pilar cyst). Treatment is by excision, or by incision followed by expression of the contents and removal of the cyst wall.
Milia
Milia are small subepidermal keratin cysts. They are common on the face in all age groups and appear as tiny white papules of 0.5 –2 mm in diameter. The contents of milia can be picked out with a sterile needle without local anaesthesia.

Premalignant epidermal tumours

Actinic keratoses
These discrete rough-surfaced pink or grey scaling macules or papules usually less than 1 cm in diameter appear on sun-damaged skin, affect the middle-aged and elderly. They classified as squamous cell carcinomas in situ but may progress to invasive squamous cell carcinomas.The effects of sun exposure are cumulative. Their rough surface is better felt than seen. Transition to an invasive squamous cell carcinoma, although rare, should be suspected if a lesion enlarges, becomes nodular, ulcerates or bleeds.
Freezing with liquid nitrogen or carbon dioxide snow is simple and effective. Shave removal or curettage is best for large lesions. Multiple lesions can be treated with 5-fluorouracil cream applied once or twice daily until there is a marked inflammatory response in the treated area. Imiquimod applied as a cream 2–3 times weekly for 16 weeks, 3% Sodium diclofenac. Photodynamic therapy, using aminolaevulinic acid followed by blue light.

Malignant epidermal tumours

Basal cell carcinoma (rodent ulcer)
This is the most common form of skin cancer, appear most commonly on the faces of the middle-aged or elderly. Lesions invade locally but, never metastasize. Prolonged sun exposure is the main factor. The slow growth of basal cell carcinoma destroys tissue locally. Untreated, a basal cell carcinoma can invade underlying cartilage or bone.
Nodulo-ulcerative This is the most common type, lesion is a small glistening translucent, sometimes umbilicated, skin-coloured papule that slowly enlarges. Central necrosis leaves an ulcer with an adherent crust and a rolled pearly edge. Coarse telangiectatic vessels often run across the surface.
Treatment in general, excision, with 0.5 cm of surrounding normal skin, is the treatment of choice for discrete tumours in patients under 60 years. Radiotherapy is also effective and is helpful when surgery is contraindicated. Cryotherapy, curettage and cautery and photodynamic therapy are sometimes useful for superficial lesions.

Squamous cell carcinoma

These tumours often arise in skin damaged by ultraviolet radiation and also by X-rays and chronic inflammation. The DNA of some types of human papilloma virus can be integrated into the nuclear DNA of keratinocytes and cause malignant transformation.
Tumours may arise as thickenings in an actinic keratosis or, de novo, as small scaling nodules; rapidly growing anaplastic lesions may start as ulcers with a granulating base and an indurated edge. Squamous cell carcinomas are common on the lower lip and in the mouth. Tumours arising in chronic draining sinuses, chronic ulcers, areas of previous X-radiation or thermal injury, or chronic inflammation are the most likely to metastasize. Squamous cell carcinoma arising in sun-exposed areas and in actinic keratoses seldom metastasize. Tumours more than 2 cm in diameter are twice as likely to recur and metastasize compared with smaller tumours. After the diagnosis has been confirmed by biopsy, low-risk tumours should be excised with a 0.5-cm border of normal skin. Wider excision (6 mm or more) is recommended for high-risk tumours. Palpation of regional nodes is important in work-up and follow-up. Radiotherapy is effective.

Malignant melanoma

Genetic Susceptibility, Malignant melanomas are most common in white people with blond or red hair, many freckles and a fair skin that tans poorly.
Sunlight Tumours occur most often,but not exclusively, on exposed skin. For melanomas, the number of sunburns seems more relevant than cumulative ultraviolet radiation dose.
Pre-existing melanocytic naevi The risk of developing a malignant melanoma is highest in those with atypical naevi, congenital melanocytic naevi or many banal melanocytic naevi.
Eighty percent of invasive melanomas are preceded by a superficial and radial growth phase, shown clinically as the expansion of an irregularly pigmented macule or plaque. Most are multicoloured mixtures of black, brown, blue, tan and pink. Their margins are irregular with reniform projections and notches. Malignant cells are at first usually confined to the epidermis and uppermost dermis, but eventually invade more deeply and may metastasize. There are four main types of malignant melanoma:
Lentigo maligna melanoma occurs on the exposed skin of the elderly. An irregularly pigmented, irregularly shaped macule (a lentigo maligna) may have been enlarging slowly for many years as an in situ melanoma before an invasive nodule (the lentigo maligna melanoma) appears.
Superficial spreading melanoma is the most common type in Caucasoids. Its radial growth phase shows varied colours and is often palpable.
Acral lentiginous melanoma occurs on the palms and soles and, is the most common type in Chinese and Japanese people.
Nodular melanoma appears as a pigmented nodule with no preceding in situ phase. It is the most rapidly growing and aggressive type.
Subungual melanomas are painless areas of pigmentation expanding under the nail and onto the nail fold (Hutchinson’s sign).
Metastatic melanoma has spread to surrounding skin, regional lymph nodes or to other organs.
As a general rule, the prognosis for those patients with non-ulcerated superficial melanomas, less than 1 mm in thickness, is excellent. An excision biopsy, with a 2–5 mm margin of clearance laterally and down to the subcutaneous fat, is recommended for all suspicious lesions. If the histology confirms the diagnosis of malignant melanoma then wider excision, including the wound of the excision biopsy, should be performed as soon as possible. A minimum of 0.5 cm clearance for melanomas in situ and 1 cm clearance is required for all invasive melanomas.Tissue is removed down to but not including the deep fascia.
If lymph node involvement is suspected clinically then the initial investigation should be with fine needle aspiration. If involvement is confirmed then formal block dissection of the involved group of nodes should be carried out. The role of α-interferon as adjuvant treatment remains controversial. Chemotherapy may be palliative in 25% of patients with advanced stage melanoma. Dacarbazine is often the drug of choice.


Tumours of the dermis
Malformations
1.Salmon patches (‘stork bites’) These common malformations, present in about 50% of all babies, are caused by dilatated capillaries in the superficial dermis. They are dull red, often telangiectatic macules,most commonly on the nape of the neck, the forehead and the upper eyelids. Nuchal lesions may remain unchanged, but patches in other areas usually disappear within a year.
2. Port-wine stains present at birth and are caused by dilatated dermal capillaries. They are pink–purple macules. Most occur on the face or trunk. They persist, and in middle age may darken and become studded with angiomatous nodules. Occasionally, a port-wine stain of the trigeminal area is associated with a vascular malformation of the leptomeninges on the same side, which may cause epilepsy or hemiparesis, or with glaucoma. Treatment with flash lamp-pumped pulsed dye laser, sessions can begin in babies.
3. Haemangiomas Capillary cavernous haemangioma (strawberry naevus) appear within a few weeks of birth and grow for a few months, forming a raised compressible swelling with a bright red surface. Spontaneous regression then follows; the surface whitens centrally and regression is complete by the age of 5 years in 50% of children and in 90% by the age of 9 years, leaving only an area of slight atrophy. Bleeding may follow trauma, and ulceration is common in the napkin(diaper) area.
Observation and encouragement. Firm pressure may be needed to stop bleeding. If lesions ulcerate, bleed repeatedly, interfere with feeding or with vision, or if giant lesions sequestrate platelets (the Kasabach–Merritt syndrome), high doses of systemic steroids should be considered; they are most successful in the proliferative phase. Prednisolone ( 2– 4 mg/kg/day ) is given as a single dose in the morning and the dosage tapered to zero after 1 month. Corticosteroid treatment is covered with a H2 blocker such as ranitidine. pulsed dye lasers are used for treating large lesions in infancy. plastic surgery is necessary for large and unsightly haemangiomas that fail to improve spontaneously or to regress with the other measures.
cherry angiomas These benign angiomas are common on the trunks of the middle-aged and elderly. They are small bright red papules and of no consequence.

Pyogenic granulomas common benign acquired haemangiomas, often seen in children and young adults. They develop at sites of trauma, over the course of a few weeks, as bright red raised, sometimes pedunculated and raspberry-like lesions which bleed easily. Lesions should be removed by curettage under local anaesthetic with cautery to the base.
Dermatofibromas These benign tumours are firm, discrete, usually solitary dermal nodules, often on the extremities of young adults. The lesions have an ‘iceberg’ effect in that they feel larger than they look. The overlying epidermis is often lightly pigmented and dimples when the nodule is squeezed. Lesions may follow minor trauma or an insect bite. It should be excised.
Lipomas are common benign tumours of mature fat cells in the subcutaneous tissue. They may be single or many and rarely familial. They are most common on the proximal parts of the limbs but can occur at any site. They have an irregular lobular shape and a characteristic soft rubbery consistency and rarely painful. They need to be removed only if there is doubt about the diagnosis or if they are painful, unsightly or interfere with activities such as sitting back against a chair.