The clinical behavior of desmoplastic melanoma

Background: Desmoplastic melanoma (DM) is a rare variant of malignant melanoma. A better understanding of the clinical course of DM will impact on its treatment. Methods: We reviewed the medical records of 59 patients with DM seen at the Mayo Clinics Scottsdale and Rochester since 1985. Results: Thirty-seven (63%) patients were male with a mean age of 62.8 years. The mean DM thickness was 6.5 mm. A total of 23 patients (39%) experienced local recurrence (LR). LR correlated with positive, unknown, or <1 cm margins. Fifty percent of patients who locally recurred subsequently developed metastatic disease. No patients were found to have positive nodal disease during ELND (16) or SLN biopsy (12). Only 1 patient (2%) developed delayed regional node metastases. Sixteen patients developed metastatic disease. The most common site was the lungs (81%). Conclusions: LR is a significant problem and correlates with an increased risk of systemic metastatic disease. With the rare occurrence of lymphatic spread, we recommend patients undergo SLN biopsy only. DM appears to preferentially metastasize to the lungs and should be targeted when evaluating the patient for metastatic disease.