Presentation
Right hip pain and progressive lameness for 4 months.
Patient Data
Ill-defined osteolytic lesion located at right ischium, with agressive lamellar periosteal reaction. Notice the adjacent increased soft tissue density.
Infiltrative and expansive osteolytic lesion located at right ischium, with agressive lamellar periosteal reaction, and extension to adjacent soft tissue and pelvis. Notice the bladder extrinsic compression.
Case Discussion
Core needle biopsy was performed and a histological diagnosis of small round cell neoplasy with CD99 and FLI-1 immunohistochemistry expression was achived. Ewing's sarcoma of Ischium confirmed and the patient was referred to oncological treatment.
Ewing's sarcoma is the most common primary bone neoplasm under 10 years of age. Radiologically, it is characterized by an osteolytic lesion of an aggressive pattern with an extensive non-mineralized soft tissue component; it belongs to the group of small round blue cell neoplasms, and presents the typical t(11;22) translocation in up to 90% of cases.