- There are two main types of skin carcinomas:
– Basal cell carcinomas (CDS), the most common (9/10 of skin carcinomas in the immunocompetent) which are slow-moving, mainly local tumours that never metastasize.
– Squamous cell or squamous cell carcinomas (CE) have a much more local evolution
aggressive and can metastasize. They account for 1/10th of skin carcinomas.
- they are developed at the expense of the same cell, the keratinocyte.
Risk factors for epithelial carcinomas:
Light phototypes (red or light skin, blond hair, blue eyes, epih hazel, inability to tan…)
Genetic diseases: xeroderma pigmentosum, albinism…
– Age: Most skin carcinomas occur after age 40
– Sun and ultraviolet rays (UV booths, UVA phototherapy) – ionizing radiation (X-rays…)
– acquired immunodepression: anti-rejection treatment after transplant …
– chronic inflammatory dermatoses: chronic ulcers – chemical carcinogens: tars (ramoneurs…), tobacco (particularly incriminated in the CE of the lower lip), arsenic (formerly used in pesticides).
Basal cell carcinomas (CBC)
These are the most common and least aggressive skin cancers (no metastasis). The CBC affects about 150 individuals per 100,000 people per year in France.
A- Positive diagnosis:
They sit with predilection on the face (exposed photo areas) and spare the mucous membranes. Many clinical forms exist; most are brought together by a common element:
The pearl. It is a translucent, whitish papule or nodule, covered with fine telangiectasies with a hair type (A vessel forming a red line).
Even in difficult diagnostic forms, a characteristic beaded border is sometimes present.
There are several anatomo-clinical varieties of varying severity:
– The nodular CBC
– The superficial CBC
– Pigmented or tattooed shapes
– Ulcerative forms
– The Scleroderma-like CBC
The nodular CBC is a firm, well-limited, smooth, rounded tumour. This is the most common form (60% of cases).
The superficial CBC (10 to 25 per cent of cases) – in situ in the epidermis, very slow evolution: erythemato-squamous oval lesion or very limited erythemaous erythmatous lesion.
The pigmented or tattooed forms are related to the presence in the tumor of melanic pigments and represent a difficult differential diagnosis with other pigmented lesions.
The ulcerative shapes, cut to the peak, sometimes bordered by a beaded bulge. When the tumour invades and destroys the underlying tissues (cartilage, bones, etc.), it is a so-called "errating" form.
Sclerodermadermiform CBC (2 to 3 percent of cases) associated intense fibrosis with tumor proliferation and came in the form of a poorly limited infiltrated atrophic closet. Its surface is whitish and its limits clinically imprecise as histologically. This form recurs more often.
If the diagnosis of skin carcinoma is often made clinically, it will usually need to be confirmed by a biopsy that will allow a histology.
C- Evolution, prognosis:
– The CBC is growing slowly.
– It does not cause metastasis (neither lymph nodes nor visceral), but has local invasive potential that can lead to significant tissue destruction. These advanced forms may require the use of mutilating surgery with sometimes heavy functional and aesthetic consequences.
– The treatment of choice is surgery because it allows a histological control of the part of exeresis and thus allows to affirm its completeness or not.
– Plastic surgery repair is required in case of extensive tumour (lambeau, graft).
– Other methods:
They are schematically reserved for inoperable patients or for certain locations. This is essentially radiotherapy and cryosurgery (liquid nitrogen). The 5-fluoro-uracile cream may be proposed to treat multiple superficial lesions. Other treatments are transforming the management of CBC: Imiquimod cream – Aldara has obtained an AMM in superficial baso.
– It is based on photoprotection and regular monitoring of patients at risk.
– After treatment of any form of CBC, regular monitoring (every year for life) is recommended to detect a recurrence of the lesion, but also because of the high risk of developing new skin carcinomas or even melanoma.
Squamous cell carcinomas or squamous cell carcinomas:
These are faster and more pronounced locoregional malignancy tumours than baso-cells and can be a source of metastasis.
The incidence of skin EC is lower than that of CBC: 10 to 20 per 100,000 inhabitants per year in France in men and 5 to 10/100,000 in women.
Sun exposure is the main causal factor, in the form of a cumulative dose. The sun is responsible for the formation of precancerous lesions on photo-exposed skin, called frequent actinic keratoses after age 60 in patients with clear phototypes.
Unlike the CBC, EC often occurs on a precancerous lesion. The most common are:
– actinic keratoses.
– old scars of deep burns and other scars (exceptional);
– genital sclerotic lichen
– actinic cheitis (lower lip): with the aggravating role of poor oral hygiene and/or smoking.
They develop on UV-exposed areas (ear pavilion, nose, forehead, etc.), more readily in light phototype subjects.
They consist of localized accumulation of keratin, in the form of a small hard yellow-brown column: they can either correspond to actinic keratosis (pre-epitheliomatous lesion) or a true CE: A histology is preferable.
B- There are three clinical forms:
– The superficial form or Bowen's disease
– The ulcerative-vegetative form
– The budding shape
- Intra-epithelial carcinoma or Bowen's disease is a lesion strictly limited to the epidermis. It presents itself as a pink or brown erythematous macule sometimes crusty, very limited, fixed in character. (difficult differential diagnosis with superficial basal cell carcinoma)
- Ulcerative form: Most common: The appearance is generally evocative: budding and ulcerated tumour, firm, adherent to deep planes, sitting most often on exposed areas (face, ears, lower lip, back of hands) often preceded by precancerous lesions. The biopsy confirms the diagnosis.
- The budding shape
C- Evolution, prognosis:
Any CE must be considered potentially aggressive. Adenopathy will always be sized in the drainage area. It usually precedes visceral metastases.
– The treatment of choice is surgery because it allows a histological control of the part of exeresis and thus allows to affirm its completeness or not. The margins are wider than for the Baso-cellular.
– Other methods: This is primarily radiotherapy.
It is based primarily on the photoprotection and regular follow-up of patients at risk as well as on the treatment of precancerous lesions in particular actinic keratoses.
The treatment of actinic keratoses: liquid nitrogen cryotherapy, creams (aldara, Efudix)
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