Extraskeletal myxoid chondrosarcoma of the leg in a child: A case report.

RATIONALE

Extraskeletal myxoid chondrosarcoma is a slow-growing soft tissue tumor of adults with a propensity for local recurrence and eventual metastasis. Only 17 pediatric and adolescent cases have been reported.

PATIENT CONCERNS

Here we present an 11-year-old boy with a 3-year history of a slowly growing painless left leg mass. Magnetic resonance imaging of the lesion revealed a subfascial well-circumscribed lesion with intramuscular extension in the medial gastrocnemius muscle of the left leg.

DIAGNOSES

He underwent wide local excision of the mass and the histomorphological and immunohistochemical findings were consistent with extraskeletal myxoid chondrosarcoma.

INTERVENTIONS

Possible radiotherapy was the further management plan.

OUTCOMES

He was in good condition with no evidence of recurrence at 6 months postsurgery.

LESSONS

Although pediatric cases of extraskeletal myxoid chondrosarcoma were reported to be aggressive, the tumor in this case demonstrated indolent behavior. Furthermore, the tumor in this case showed primitive round cell foci which adds to a previous study that especially reported this morphology in pediatric cases.