Metastatic melanoma: clinicopathologic features and overall survival comparison.

Introduction: Five-year survival for melanoma with distant metastasis has been reported as 25%. This study evaluates the relationship between known and uncertain clinicopathologic parameters and overall survival (OS) for metastatic melanoma patients.

Methods: Metastatic melanoma cases (n = 122, 45 female, 77 male) that were metastatic at the time of diagnosis or referred for molecular pathological analysis were included. Survival was analyzed using the Kaplan-Meier method with comparisons performed by the log-rank test.

Results: The mean age of diagnosis at the time of metastasis was 56 years (range 19-89). The 1-year, 2-year, and 5-year OS rates were 44%, 27%, and 17%, respectively. Cox multiple regression analysis identified the following as independent poor prognostic factors for OS: perivascular pseudorosette formation (hazard ratio [HR]: 12.821, p = 0.045), lung compared to skin and subcutaneous soft tissue and to lymph node, specific cytologic features such as clear cytoplasm (p = 0.043), and hyperchromatic nuclei (HR: 98.605, p = 0.005) compared to vesicular chromatin pattern. At the end of the study, 26 (21%) of the patients were alive, and 96 (79%) were deceased.

Conclusions: In conclusion, perivascular pseudorosette formation, first described as a case report in primary and metastatic melanoma, may represent a new prognostic and diagnostic histopathological finding for metastatic melanoma.