Objective: To perform a retrospective clinico-pathological and immunohistochemical analysis of malignant melanomas.
Methods: One-hundred sixty consecutive cases diagnosed in the Department of Pathology of the County Emergency Clinical Hospital of Tîrgu Mureş, Romania, between January 2000 – December 2009, were used. Of these, 47 cases were melanoma metastases that were excluded from the study; this research was focused on the study of 113 primary melanomas (PMs). In 20 cases of PMs (11 cutaneous, 5 choroidal, and 4 melanomas of the anal canal) immunohistochemical stains were performed using the antibodies p53, Ki67, ER (estrogen receptor), CD8 and CD31.
Results: Cutaneous PMs prevailed (83%) followed by choroidal (11%), digestive tract (4%) and nasal mucosa PMs (2%). Independent of their location, PMs predominantly affected females (58%) over age 50. Regarding cutaneous cases, lower limbs (49%) were more affected, followed by the head and neck (18%) and the trunk (18%). We noted negativity or low p53-nuclear positivity in cutaneous and digestive tract PMs; p53 was overexpressed in choroidal melanomas. On the other hand, although the proliferative index Ki67 was also quite low in cutaneous PMs, its percentage increased in choroidal and digestive tract PMs. CD8 was positive in cutaneous PMs and negative in choroidal and digestive tract cases. While in cutaneous PMs we noted a predominated angiogenesis by intussusception, in digestive tract melanomas there was a predominance of sprouting and pseudoglomeruloid mechanisms.
Conclusions: Choroidal PMs display the highest p53 and Ki-67 expression, compared to cutaneous MMs. Tumor angiogenesis seems to present a specific pathway in cutaneous PMS compared to the gastrointestinal cases.