Desmoplastic melanoma in Sweden in 2009–2022: A population‐based registry study demonstrating distinctive tumour characteristics, incidence and survival trends

• DOI: 10.1111/jdv.20522
• Publication Date: 2025-01-08T12:44:17Z
• Authors: Yodit Girmay; Francesca Portelli; Rasmus Mikiver; Jan Lapins; Karolin Isaksson; Hildur Helgadottir
• Keywords: Lentigo maligna melanoma; Lentigo maligna; Lentigo; Nodular melanoma; Superficial spreading melanoma

Abstract Background Desmoplastic melanoma (DM) is a rare subtype, accounting for less than 5% of primary cutaneous invasive melanomas. DM often arises in chronically sun‐exposed skin, older individuals. While the incidence has increased globally, trends specific to are documented and studies on survival outcomes inconsistent. Objectives To study patient tumour characteristics, desmoplastic comparison with other subtypes using data from population‐based Swedish Melanoma Registry (SweMR). Methods Clinicopathological variables were obtained SweMR, patients diagnosed melanomas Sweden 2009 2022. Incidence rates per 100,000 inhabitants calculated. cases identified compared across DM, superficial spreading (SSM), nodular (NM) lentigo maligna (LMM). Survival was analysed Kaplan–Meier Cox regression methods. Results Among 48,945 melanomas, 388 (0.8%) as DM. The ranged between 0.1 0.4 100,000, without evident rise, beside certain peak 2019–2020 men. had thickest tumours ( p < 0.001). When adjusting baseline prognostic factors, an improved melanoma‐specific (HR 0.36, 95% CI 0.26–0.49). No significant improvement observed 2015–2022 those 2009–2014 (adjusted HR 0.99, 0.45–2.14), whereas showed 0.74, 0.68–0.80). Conclusion In contrast rising subtypes, remained more stable over recent years. Despite presenting adverse features, superior when these factors. However, introduction anti‐PD‐1 therapy not significantly patients.