Background: We defined melanoma distribution in a large series of Turkish patients and evaluated theprognostic parameters of melanomas. Materials and
Methods: A total of 1574 patients’ data was retrospectivelycollected at 18 centers in Turkey. Demographic characteristics were questioned and noted. Prognostic parametreswere evaluated based on sentinel lymph node involvement.
Results: Mean age was 56.7 (4-99) years. While 844(53.6%) cases were male, 730 (46.4%) cases were female. One thousand four hundred forty-seven (92%) caseswere invasive melanoma and 127 (8%) cases were in-situ melanoma. The most common histopathological formwas the superficial spreading melanoma (SSM) which was found in 549 patients (37.9%). It was followed bynodular melanoma in 379 (26.2%), acral lentiginous melanoma (ALM) in 191 (13.2%) and lentigo malignamelanoma in 132 (9.1%), respectively. On univariate analysis, lymphovascular invasion (p<0.001), tumorthickness (p<0.001), histopathological subtype (p<0.001), Clark level (p=0.001), ulceration (p<0.001), ≥6/mm2mitosis (p=0.005), satellite formation (p=0.001) and gender (p=0.03) were found to be associated with sentinellymph node positivity. Regression was associated with sentinel lymph node negativity (p=0.017). According tomultivariate analysis, lymphovascular invasion and tumor thickness were significant independent predictivefactors of SLN positivity. Patient age, tumor localization, precursor lesions, lymphocytic infiltration andneurotropism were not related with sentinel lymph node involvement.
Conclusions: In this retrospective analysis,it was found that the prevalence of SSM is at a lower rate while the prevalence of ALM is at a higher rate whencompared to western countries. According to Breslow index; most of the melanoma lesions’ thickness weregreater than 2 mm, corresponding Clark IV. Vascular invasion and tumor thickness are the most importantfactors for sentinel lymph node involvement.