The 7 years old girl has presented at the orthopedic in the out-patient department with a palpable small lump over mid-shin. There was a history of the leg being hit against a school desk about 6 months ago. The child had not received any active treatment then.

The child is in good health with no constitutional symptoms. The swelling is minimally tender on deep touch. X-rays are enclosed for a possible diagnosis or set of differential diagnosis.