Surgery. 2025 Nov 3;190:109850. doi: 10.1016/j.surg.2025.109850. Online ahead of print.
ABSTRACT
BACKGROUND: Atypical lipomatous tumors (also known as well-differentiated liposarcoma) are locally aggressive, low-malignant soft tissue tumors composed of mature adipocytes and stromal cells with nuclear atypia. Although these tumors do not metastasize, they exhibit a significant risk for local recurrence and potential for dedifferentiation into high-grade liposarcomas. Despite consensus that complete surgical excision is the gold standard, the impact of positive margins remains unclear. This study evaluated the role of surgical margins in atypical lipomatous tumor recurrence.
METHODS: We retrospectively reviewed medical records of patients who underwent marginal resection of atypical lipomatous tumors between 2005 and 2025 at a single center. Demographic data, tumor characteristics, surgical treatment, pathology reports, recurrence rates, and risk of dedifferentiation were analyzed. Recurrence-free survival was estimated using Kaplan-Meier analysis, and factors associated with recurrence were evaluated using multivariate Cox proportional hazards regression.
RESULTS: Fifty-four patients were included in the study. The median follow-up period was 24.5 months (range 6-172 months). Complete (R0) resection was achieved in 32 patients, whereas 22 patients had microscopically positive margins (R1). Local recurrence occurred in 11 patients (20.4%) with a median time to recurrence of 31.8 months (range 11-65.7 months). Recurrence occurred in 18.8% of R0 and 22.7% of R1 resections, with no significant difference in recurrence-free survival (P = .42). No cases of distant metastasis were observed. Dedifferentiation to grade 2 liposarcoma occurred in 2 patients (3.7%).
CONCLUSION: Marginal resection of atypical lipomatous tumors offers an acceptable local recurrence rate while allowing the preservation of critical structures and function. Regular postoperative surveillance enables early identification of tumor recurrence and potential dedifferentiation.
PMID:41187416 | DOI:10.1016/j.surg.2025.109850