ABSTRACT
BACKGROUND:
Extraskeletal myxoid
chondrosarcoma (EMC) is a rare malignant
soft tissue sarcoma (STS) that accounts for less than 3% of all soft
tissue tumors. The conventional
treatment for primary EMC is wide local excision with or without
radiation therapy. MATERIALS AND
METHODS:
This study was a retrospective
review of all EMC cases treated within a single institution between 1992 and 2019. EMC was diagnosed using a combination of histologic morphology and immunostaining, with confirmatory
fluorescent in situ hybridization. Overall
survival (OS) and
disease-specific
survival (DSS) were defined using
Kaplan-Meier analysis.
RESULTS:
Fifteen
patients were evaluated, including 11
males and four
females. The average age at presentation was 51.7 ± 20.4 years and the mean follow-up
time was 61.5 months (range, 5-286 months). The average resected
tumor size at largest dimension was 7.14 cm (range, 2.4-18.7). Twelve of fifteen (80%)
patients underwent wide local excision, and nine of the twelve (75%) underwent local
radiation therapy. The 1-, 5-, and 10-year OS was 80% (95% CI, 59.8-100), 72% (95% CI, 48.5-95.5), and 72% (95% CI, 48.5-95.5), respectively. The 1-, 5-, and 10-year DSS was 92.3% (95% CI, 77.8-100), 83.1% (95% CI, 61.5-100), and 83.1% (95% CI, 61.5-100), respectively. At last follow-up, 11
patients were alive and ten (90.9%) were
disease free.
CONCLUSIONS:
Extraskeletal myxoid
chondrosarcoma is a very rare STS most often seen in
males and in the
extremities. Our cohort was too small to provide meaningful
statistical analysis; however, we observed lower rates of local
recurrence in
patients treated with
radiation.
