Case report: Primary pleural giant extraskeletal Ewing sarcoma in a child

Area of Science:

• Oncology
• Pediatric Oncology
• Radiology

Background:

• Primary extraskeletal Ewing sarcoma (EES) is a rare small round cell malignancy, accounting for less than 1% of all sarcomas.
• EES typically occurs in the trunk and lower limbs, with pleural involvement being exceptionally rare and prone to misdiagnosis.

Observation:

• An 11-year-old boy presented with a 6-month history of unexplained left shoulder pain, chest wall tenderness, and limited shoulder mobility.
• Imaging revealed an irregular left thoracic soft tissue mass with pleural and adjacent first rib bone destruction.
• A CT-guided biopsy confirmed extraskeletal Ewing sarcoma.

Findings:

• The patient received alternating cycles of vincristine, doxorubicin, and cyclophosphamide (VDC) and isocyclophosphamide and etoposide (IE) chemotherapy.
• Clinical improvement and pain relief were observed after five chemotherapy cycles.
• However, repeat MRI demonstrated no reduction in the size of the pleural mass, suggesting treatment resistance.

Implications:

• This case underscores the diagnostic challenges of rare extraskeletal Ewing sarcoma presentations.
• The observed lack of tumor response to standard chemotherapy highlights the need for further research into alternative or novel therapeutic strategies for refractory EES.
• Early and accurate diagnosis through advanced imaging and biopsy is crucial for appropriate management of this rare pediatric malignancy.