]> 2026-07-31T09:41:17+00:00 WBR0202 0 en Double-bubble sign Punched-out erosions with over-hanging cortical bone Punched-out erosions with over-hanging cortical bone (rat-bite erosions) are characteristic of gout. Gout is an acute monoarthritis caused by precipitation of the needle-shaped, negative-birefringent monosodium urate (MSU) crystals. It is associated with hyperuricemia and results in podagra, a painful MTP joint of the big toe. Onion-skin appearance Onion-skin appearance is a radiographic finding commonly observed in Ewing's sarcoma. Glistering mass within the medullary cavity Erlenmeyer flask deformity Pathology A 9-year-old boy is brought to the pediatrician's office for persistent pain in his right leg. The mother explains that the patient's symptoms have been progressively worsening for the past 2 months. Upon further investigation, the patient reports recent unintentional weight loss despite normal appetite. Physical examination is remarkable for tenderness over the right femoral diaphyseal area. Additional testing reveals a right femoral bone mass with a histopathological analysis that demonstrates small, round, blue cells that are CD99-positive. What is the most likely radiographic finding of this patient's right femur? C Oncology 2020-10-27T23:44:40Z 2459150.4893519 WBR0202