Assessment of Risk Factors Correlated with Satellites and In-Transit Metastases in Primary Cutaneous Melanomas

Background and Objectives: This study aimed to identify the risk factors of primary cutaneous melanomas associated with microsatellites, satellites, and in-transit metastases. Materials and Methods: We performed a retrospective study on patients diagnosed with invasive primary cutaneous melanomas in two pathology departments. The cases were distributed into two groups, comparing the clinical-pathological features of cases that presented microsatellites, satellites, and in-transit metastases with cases that did not present microsatellites, satellites, and in-transit metastases. Results: From the total number of primary invasive cutaneous melanomas diagnosed (n = 204), 22% presented microsatellites, satellites, and in-transit metastases (n = 46). The presence of microsatellites, satellites, and in-transit metastases was strongly correlated with a Breslow index > 4 mm, a Clark level of IV or V, and a pT3 or pT4 pathological stage (p < 0.0001). Those cases were also associated with lymphovascular invasion (p = 0.0013), ulceration of the primary melanoma (p = 0.0037), and an increased mitotic rate (p = 0.0078). The presence of microsatellites, satellites, and in-transit metastases is associated with higher rates of lymph node metastases (p = 0.0006) and recurrence (p = 0.0282). Conclusions: The most important risk factors associated with microsatellites, satellites, and in-transit metastases are represented by a Breslow index > 4 mm, a Clark level of IV or V, and an advanced pathological stage.