WIDE local excision and Mohs surgery are the leading treatments for melanoma patients with positive tumor margins, according to findings presented at the American Society for Dermatologic Surgery Annual Meeting. Jennifer L. Strunck, a dermatology resident at Oregon Health & Science University, Portland, Oregon, emphasized that while standard excision is typically effective, positive margins still occur in a notable subset of cases, particularly on the upper extremities.
Strunck reported that positive margins following standard excision for melanoma are rare, with incidence rates ranging from 0% to 6.3%. Higher rates of up to 20% are observed in melanomas of the head and neck. Risk factors for positive margins include advanced age, certain melanoma subtypes such as nodular and desmoplastic, and tumors located on the lip, eyelid, or face.
The study reviewed data on 67 patients with confirmed positive margins after melanoma excision. Tumors were most frequently located on the upper extremities (43.2%), followed by the head, neck, and trunk (each 19.4%). Lower extremities and other areas showed far lower incidences.
Treatment choices varied across tumor stages, with wide local excision being the preferred approach in 59.1% of cases, followed by Mohs surgery in 22.7%. Observation was chosen for select early-stage tumors (13.6%), particularly when tumor size was minimal. Strunck noted that imiquimod was rarely used, limited to 0.3% of in situ cases and mainly for head and neck tumors.
“While excision remains the top choice after positive margins, Mohs, observation, and imiquimod are also viable options based on the tumor’s characteristics,” Strunck said. The study underscores the need for tailored approaches to positive margins, with surgical excision and Mohs emerging as leading strategies.
Reference: Strunck JL et al. Positive margins after standard excision of cutaneous melanoma. American Society for Dermatologic Surgery Annual Meeting, October, 17-20, 2024, Orlando, Florida.
Anaya Malik | AMJ
