Isolated Unilateral Orbital Metastasis From Ewing Sarcoma Detected on FDG PET/CT Scan

Abstract

Ewing sarcoma is the second most common primary malignant bone tumor that usually affects diaphysis of long bones during the second decade of life. Isolated unilateral orbital metastasis from this tumor presenting as proptosis is extremely rare. Here we report a case of 11-year-old boy where whole-body FDG PET/CT scan detected primary an Ewing sarcoma site in the left femur and isolated orbital metastasis in the left eye. Follow-up PET/CT scan after 6 cycles of chemotherapy showed resolution of the previously seen lesions.

Features of Metastatic Ewing Sarcoma

“…It seems that the occurrence of metastasis, which can be overt or subclinical, seems to be a recurring phenomenon in almost all patients. Such metastatic sites can also be quite distant and rare from the primary site of the tumor, including small bowel, oral cavity, pancreas, spine, and orbital cavities among others (57)(58)(59)(60)(61)(62)(63)(64)(65). In a dramatic presentation, ES/ PNET metastasized into the jejunum causing intussusception, one of the most life-threatening chirurgical emergency (65).…”

Challenges in primary orbital Ewing sarcoma: A case report

“…EWS is more commonly found in males during the second decade of life [5]. POES accounts for only a small portion of EWS cases [6][7][8][9][10][11].…”

Recurrent Metastatic Ewing Sarcoma Involving Only in the Muscles of Extremities Shown on FDG PET/CT

“…7 Metastasis in multiple muscles without other sites of involvement is an unusual feature of Ewing sarcoma recurrence. FDG PET/CT findings of some unusual sites of both primary extraosseous Ewing sarcomas [8][9][10][11] and metastases 12,13 have been reported before. Here we present the case of a 6-year-old patient in whom FDG/PET CT demonstrated multifocal hypermetabolic nodular muscle metastases in the extremities without any other locations of tumor involvement.…”