Desmoplastic melanoma - The step-child in the melanoma family?

Background: and Objectives Desmoplastic melanoma (DM) is a rare variant of cutaneous melanoma. Our goal was to study the surgical management of DM, identify prognostic factors, and impact of treatment options. Methods Patients with DM (n=1,735) were identified from the Surveillance, Epidemiology, and End Results database (1988-2006). Results The median age of the study population was 69 years and overall survival (OS) at 5 years 65%. DM was more common in males (65%), most commonly found on the head and neck (51%), and had a mean thickness of 2.97 mm. Patients undergoing a wide local excision (WLE; ≥1 cm) had improved 5-year OS compared to a simple excision (<1 cm) or biopsy alone (67% vs. 60% vs. 45%, respectively, P < 0.001). Of 505 patients (29%) undergoing sentinel node biopsy (SLNB), only 14 (2.8%) were positive. Traditional prognostic factors such as Breslow thickness, nodal positivity, and ulceration did not predict survival. On multivariate analysis only adjuvant radiation therapy [HR 1.65 (95% CI 1.17-2.31)] and WLE correlated with survival [HR 0.47 (95% CI 0.32-0.69)]. Conclusions: Desmoplastic melanoma does not share traditional prognostic factors with the melanoma family. Surgical resection with wide margins is needed to optimize survival and routine SLNB may be unnecessary.