Do you offer radiation in the setting of a resected desmoplastic melanoma with negative margins given that several retrospective studies show a local control benefit?   

Desmoplastic melanoma represents a minority of cutaneous melanoma lesions and typically occurs in the head and neck region, more commonly in elderly men, and typically diagnosed with an advanced Breslow depth. Historically, the outcomes associated with desmoplastic melanoma following resection were...

An ongoing international randomized controlled trial will help answer your question, once complete. You are encouraged to refer to your patients to centers enrolling patients on this trial, to consider enrollment: https://clinicaltrials.gov/ct2/show/NCT00975520

Malignant melanoma, even with "clean" margins can still recur locally.  I routinely treat these lesions postoperatively with a wide margin beyond the resection area, generally 1.5-2 cm.  I do not prophylactically treat the node groups.  Treatment is almost always electrons, 300 cGy, B...