CT
bone window
bone window
What is the final diagnosis, determined by contrast injection?
The long segment filling of the lesion with extravasation of contrast through the fracture sites proves it's cystic nature, solidifying the diagnosis of a unicameral bone cyst.
Following core biopsy and FNA attempts, 20 mL of 4:1 dilute contrast was injected through the coaxial needle into the cavity of the lesion without resistance. There is long segment of filling of the lytic lesion, with spillage of contrast through the fracture sites into the adjacent subcutaneous tissues, suggesting the lesion is cystic in nature.