Retrospective registry for acral melanoma in Lebanon: A 12-year single-center experience in the MENA region.

Abstract

e21599 Background: Acral melanoma (AM) is a rare, aggressive melanoma subtype that primarily affects non-hair-bearing skin, such as the palms, soles, and subungual regions. Despite its higher prevalence in non-European populations, AM remains underreported in the Middle East and North Africa (MENA) region. This study aims to analyze the demographic, clinicopathological, and treatment characteristics of AM patients at the American University of Beirut Medical Center (AUBMC), a major tertiary referral center in Lebanon, over a 12-year period. Methods: This retrospective study included all adult patients diagnosed with AM at AUBMC between January 2012 and January 2024. Among 331 melanoma cases diagnosed during this period, 26 patients (7.85%) were identified as having AM based on histological subtype or tumor location (palmar, plantar, subungual). Demographic data, tumor characteristics, treatment modalities, and clinical outcomes were extracted and analyzed from electronic health records. Results: The median age at diagnosis was 58.5 years (IQR: 25.3), with a near-equal gender distribution (53.8% female). Most patients (96.2%) were of Middle Eastern descent, with plantar involvement being the most common site (80.8%). The median Breslow thickness was 3.9 mm (IQR: 4.45), and ulceration was present in 55% of cases. Surgery was the most common initial treatment in 88.5% of patients, including wide local excision (50%), amputation (19.2%), and excisional biopsy (19.2%). Despite surgery, positive margins were observed in 54.5% of cases. At diagnosis, 38.5% of patients had stage II disease, and 23.1% developed metastases, with a median progression time of 19.1 months (IQR: 26.9). Recurrence occurred in 26.9% of cases, with a median recurrence time of 6.3 months (IQR: 2.6). Sentinel lymph node biopsy was performed in 46.2% of cases. Immunotherapy was administered to 34.6% of patients. Genetic testing was performed in 34.6% of patients, identifying BRAF mutations in 11.1% of those tested. At the last follow-up, 92.3% of patients were alive, with a median follow-up time of 24.5 months (IQR: 43.0). Conclusions: This study, the first AM registry in Lebanon and the MENA region to date, provides valuable insights into the clinicopathological characteristics and treatment patterns of this rare melanoma subtype. The high rate of positive margins despite surgical intervention highlights the challenge of achieving complete resection in AM. Further research into immunotherapy and other adjuvant treatments is needed to improve outcomes. Establishing a multicenter registry could enhance data collection, guide personalized treatment strategies, and support early detection efforts for AM patients in the MENA region.