Anatomical patterns and sequence of distant metastasis in myxoid liposarcoma: a Korean single-center retrospective cohort study

Myxoid liposarcoma (MLS) is a distinct soft tissue sarcoma subtype with a predilection for extrapulmonary metastasis. Cohort data describing the metastatic pattern in Korean patients are limited, and the within-patient temporal sequence of pulmonary and extrapulmonary metastasis has received less systematic attention. We retrospectively reviewed 47 patients with histologically confirmed myxoid liposarcoma who underwent surgical resection at a Korean tertiary sarcoma referral center between January 2008 and December 2024. For patients with distant metastasis (DM), the dates of first pulmonary and first extrapulmonary involvement were captured separately. Outcomes included the occurrence and anatomical distribution of DM, the within-patient temporal sequence of pulmonary versus extrapulmonary involvement, local recurrence (LR), overall survival (OS), distant metastasis-free survival (DMFS), and post-metastasis survival. Median age at surgery was 49 years; 70.2% were male and 89.4% had lower-extremity primary tumors. Median follow-up was 56.9 months. Distant metastasis occurred in 15 patients (31.9%); 14 of 15 (93.3%) had extrapulmonary involvement at first metastasis. Among the 7 patients who developed both pulmonary and extrapulmonary disease, extrapulmonary metastasis preceded pulmonary involvement ( n = 4) or was detected simultaneously ( n = 3); overall, extrapulmonary disease tended to appear first, with only 1 of the 15 patients developing pulmonary metastasis first. MRI-based modalities accounted for 7 of 15 first-metastasis detections. Local recurrence occurred in 6 patients (12.8%), more frequently among those referred after outside surgical intervention (4 of 16) than among those presenting with primary disease (2 of 31). The 2- and 5-year OS were 82.0% and 73.5%, respectively; 2- and 5-year DMFS were 86.4% and 79.8%. Median survival from first distant metastasis was 33.7 months. In this Korean tertiary-center cohort, myxoid liposarcoma exhibited an extrapulmonary-dominant metastatic pattern, and extrapulmonary involvement tended to precede or accompany pulmonary disease at the individual-patient level. These observations support surveillance that covers extrapulmonary sites, in line with current NCCN recommendations for myxoid liposarcoma.