Sursa: melanocite -cel mai frecvent din pielea fara nev -mai rar dintr-un nerv displastic -91% cutanate, 5% oculare, 1% la niv. mucoaselor, 3% nu se poate identifica tu. primara (doar metasatazele) Alte tu. ale pielii: -carc. scuamoase -carc. bazocelulare
Epidemiologia 6. prin incidenta in USA cel mai frecvent la rasa alba; I mult mai mica la cea neagra si asiatica B/F=1/1
Patogeneza-factori de risc 70%-mutatii sau deletii in gena CDKN2A =>activarea unor gene cu productia de proteine ce inhiba genele supresoare tumorale p53 si RB radiatia UV (UVC>UVB>UVA) pers. cu pielea deschisa -doar in 10% a cazurilor predispozitie genetica -sindromul nevilor displazici
Nevii displazici ABCD mnemonic: asymmetry, border irregularity, color variation, diameter greater than 6 mm.
Indicele Breslow si Clark Breslow Thickness First reported by Alexander Breslow in 1970, the Breslow thickness is defined as the total vertical height of the melanoma, from the very top (called the "granular layer") to the area of deepest penetration in to the skin. An instrument called an "ocular micrometer" is used to measure the thickness of the excised (removed) tumor. In general, the higher the Breslow thickness, the worse the prognosis (keep in mind that these survival rates are averages and may not reflect your individual case): less than 1 mm: 5-year survival is 95% to 100% 1 to 2 mm: 5-year survival is 80% to 96% 2.1 to 4 mm: 5-year survival is 60% to 75% greater than 4 mm: 5-year survival is 37% to 50% Due to its accuracy in predicting outcomes, the Breslow thickness has been incorporated into the standard TNM staging system for melanoma. In 2001, a large study confirmed the importance of Breslow thickness as one of the three most important prognostic factors in melanoma, along with tumor (T) stage and the existence of ulceration (broken skin, bleeding, swelling). Clark Level The Clark level refers to how deep the tumor has penetrated into the layers of the skin. This system was originally developed by W. H. Clark, MD back in 1966. Clark levels are officially defined as follows: Level I: confined to the epidermis; called "in situ" melanoma; 100% cure rate at this stage Level II: invasion of the papillary (upper) dermis Level III: filling of the papillary dermis, but no extension in to the reticular (lower) dermis Level IV: invasion of the reticular dermis Level V: invasion of the deep, subcutaneous tissue Since 2002, Clark's levels have been used less and less for calculating prognosis, since research has shown them to be less predictive of outcome, less reproducible and more subjective than the Breslow depth. Other disadvantages of this system are that it is often very difficult to differentiate between Clark Level II and Level III, and it can't be used on melanomas of the palms and soles. There is one instance in which Clark’s levels continue to be used to predict prognosis: in patients with thin (less than 1.0 mm) melanoma, a Clark’s level IV or V lesion portends a worse prognosis. For this reason, pathologists continue to include the Clark’s level along with Breslow thickness and existence of ulceration in their reports