Clinicopathologic features and survival in Spitzoid malignant melanoma and conventional malignant melanoma.

Abstract

Although recent advances in genetics have revealed distinct mutational profiles and molecular signaling pathways associated with Spitzoid malignant melanoma (SMM), less is known about the clinicopathologic characteristics and behavior of SMM compared with conventional melanoma. We sought to determine the clinicopathologic characteristics and mortality risk associated with SMM and conventional malignant melanoma. We conducted a retrospective study of 30 patients with SMM and 30 patients with conventional melanoma. The two groups were matched by age, gender, and depth of tumor invasion. Additional patient- and tumor-level characteristics were compared between groups and regression modeling was used to assess relative mortality risk. Unadjusted analyses of SMM and conventional malignant melanoma revealed no significant differences in clinical impression, anatomic location, mitotic rate, and presence of ulceration. Sentinel lymph node biopsy, completion lymphadenectomy, and visceral metastases did not differ between groups. Cox proportional hazards regression showed no differences in mortality between Spitzoid and conventional melanoma. Small sample size, short follow-up duration, and residual confounding may limit the accuracy and generalizability of our results. SMM and conventional malignant melanoma differ in some clinicopathologic features. We did not find a statistically significant difference in mortality between the two.