Extraskeletal myxoid chondrosarcoma arising from the clavicle

Area of Science:

• Oncology
• Pathology
• Radiology

Background:

• Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue sarcoma.
• EMC typically arises in deep soft tissues of the extremities and trunk.
• Originating from the clavicular periosteum is an exceptionally uncommon presentation.

Observation:

• A 48-year-old male presented with a mass.
• Radiography and CT scans of the clavicle showed no osteolytic lesion or periosteal reaction.
• MRI revealed a T1 isointense and T2 homogeneous hyperintense mass.

Findings:

• Histopathological examination of the resected tumor confirmed extraskeletal myxoid chondrosarcoma.
• The tumor arose from the periosteum of the clavicle, an unusual location.
• Diagnostic challenges were noted, even with histological examination of biopsy specimens.

Implications:

• This case highlights the importance of considering rare diagnoses in unusual locations.
• Accurate preoperative diagnosis of EMC can be challenging, requiring a combination of imaging and histology.
• Detailed clinicopathological reporting of rare tumors improves understanding and diagnostic criteria.