2-Case presentation
A 38-year-old male patient presenting for severe epigastric pain radiating to the back of 3-days duration. He described his pain as pressure-like, intermittent with an intensity of 10 out of 10. Of note, the patient was initially diagnosed with EES of the soft tissue on the plantar surface of the left foot (8*3,6cm) with immunochemistry that showed expression of CD99. He underwent surgical resection below knee amputation with biopsy revealing small round blue cell destructing the bone and infiltrating the soft tissue.