- There are two main types of skin cancer :
– The carcinomas basal cell (CBC), The most common (9/10 skin cancers in immunocompetent) which are tumors of & rsquo; slow evolution, mainly local, never metastasize.
– The carcinomas spinocellulaires or squamous (THIS) have a local change much
aggressive and can metastasize. They represent 1 / 10th of skin cancer.
- they are developed at the expense of the same cell, keratinocyte.
factors from risk of the epithelial carcinomas :
– genetic factors :
Phototypes clairs (red or pale skin, Blond hair, blue eyes, freckles, inability to tan ...)
genetic diseases : xeroderma pigmentosum, albinisme ...
– Age: la plupart des carcinomes cutanés surviennent après 40 ans
– Sun and ultraviolet rays (Sunbeds, UVA phototherapy) – ionizing radiation (X-rays…)
– acquired immune: anti-rejection treatment after transplant ...
– chronic inflammatory dermatoses : chronic ulcers – chemical carcinogens : tars (ramoneurs ...), tobacco (particularly implicated in the EC of the lower lip), arsenic (formerly used in pesticide).
basal cell carcinomas (CBC)
These are the most common and least aggressive of the skin cancers (no metastasis). The CBC concern in France about 150 individuals for 100 000 inhabitants per year.
A- Diagnostic positive :
They sit with favorite face (Photo exposed areas) and save the mucous. Many clinical forms exist; most are united by a common element :
the pearls. C & rsquo; is a papule or nodule translucent, whitish, traveled fine telangiectasia type capillary scalp (= Vessel forming a red line).
Even in the forms of diagnosis difficult, a characteristic beaded edge is sometimes present.
There are varieties clinicopathological from severity variable:
– The nodular BCC
– The superficial BCC
– Pigmented forms or tattooed
– The forms ulcerative
– The CBC sclerodermiform
The CBC nodular is a farm tumor, very limited, smooth, rounded. C & rsquo; is the most common form (60 p. 100 cases).
The CBC superficial (10 at 25 p. 100 cases) = In situ in the epidermis, d & rsquo; very slow evolution : lesion oval erythematous scaly erythematous or limited well.
The forms pigmented or tattooed are related to the presence in the tumor and melanin pigments represent a differential diagnosis difficult with other pigmented lesions.
The forms ulcerous, hewn peak, sometimes lined & rsquo; a pearl bead. When the tumor invades and destroys underlying tissues (cartilage, the…), it is a form called "Boring".
The CBC sclerodermiform (2 at 3 p. 100 cases) combines intense fibrosis in tumor proliferation and comes in the form of & rsquo; an atrophic closet infiltrated badly limited. Its surface is whitish and vague limits clinically as histologically. This recurrence form more often.
B- anatomy-pathological :
If the diagnosis of skin carcinoma is often made clinically, it will usually confirm by biopsy allowing histology.
C- Evolution, prognosis :
– The CBC is slow growing.
– It n & rsquo; results not from metastasis (or lymph node or visceral), but a local invasive potential that can result in significant tissue destruction. These advanced cases may require the use of mutilating surgery to functional and aesthetic sometimes severe consequences.
D- Treatment :
– The treatment of choice is the surgery because it allows a histological control room d & rsquo; excision and thus allows & rsquo; assert full or not.
– A repair plastic surgery is necessary in case of extensive tumor (lambeau, graft).
– Other methods:
Elles sont schématiquement réservées à des malades inopérables ou pour certaines localisations. Il s’agit essentiellement de la radiothérapie et de la cryochirurgie (liquid nitrogen). The 5-fluorouracil cream can be proposed for treating multiple superficial lesions. D & rsquo; other treatments are transforming the management of CBC : Imiquimod cream Aldara = obtained a marketing authorization in superficial basal.
E- Prevention :
– Elle repose sur la photoprotection et le suivi régulier des malades à risques.
– Après traitement de toute forme de CBC, regular monitoring (every year for life) is recommended to screen for recurrence of the lesion, but also because of the high risk of & rsquo; emergence of new skin cancers, or melanoma.
The carcinomas spino–cell or carcinomas squamous :
These are locoregional malignant tumors of more rapid and more pronounced than basal cell and can be a source of metastases.
L & rsquo; incidence of skin EC is lower than that of CBC: 10 at 20 for 100 000 inhabitants / year in France with the & rsquo; man 5 at 10/100 000 residents in women.
L & rsquo; sun exposure is the main causal factor, as cumulative dose. The sun is responsible for the formation of precancerous lesions on the skin photo-exposed, called actinic keratoses common after 60 years in patients clear phototype.
Unlike the CBC, CE often occurs on a precancerous lesion. The most common are:
– the kératoses actiniques.
– radiodermatitis ;
– old scars of deep burns and other scars (exceptional) ;
– genital lichen sclerosus
– actinic cheilitis (bottom lip): with the aggravating role of poor oral hygiene and / or smoking.
The kératoses actiniques =
They develop on the areas exposed to UV (Pavilion ears, nose, front…), more likely in patients clear phototype.
the cutaneous horns =
They consist of the & rsquo; localized accumulation of keratin, as d & rsquo; a small tan lasts column: they can either match actinic keratosis (lesion Pre-epitheliomatous) is a real EC : Histology is better.
B- On distinguished three forms clinics :
– The surface shape or Bowen's disease
– The shape ulcerative vegetating
– The burgeoning form
- The carcinoma intraepithelial or sickness from Bowen is strictly limited to the epidermis lesion. It comes as a erythematous macula pink or brown sometimes crusty, very limited, fixed character.(differential diagnosis difficult with the superficial basal cell carcinoma)
- ulcérovégétante form: The most common : L & rsquo; appearance is usually indicative : tumor budding and ulcerated, closed, adherent to the deep planes, serving most often on exposed areas (face, ears, bottom lip, back of the hands) often preceded by precancerous lesions. The biopsy confirmed the diagnosis.
- The form budding
C- Evolution, prognosis :
All EC should be considered potentially aggressive. We always look for a lymphadenopathy in the area drainage. It usually precedes the visceral metastases.
D- Treatment :
– The treatment of choice is the surgery because it allows a histological control room d & rsquo; excision and thus allows & rsquo; assert full or not. The outset margins are wider than for Basal cell.
– Other methods : It s & rsquo; is all about radiotherapy.
E- Prevention :
It is based primarily on photoprotection and regular monitoring of risk patients as well as the treatment of precancerous lesions in particular actinic keratoses .
The treatment of the kératoses actiniques : cryotherapy with liquid nitrogen, creams (aldara, Efudix)