Name : Morteza
Family :Sanei Taheri
Resident : Payam Asadi
Gender : Female
Age : 12
A 12 Y/O girl with low back pain
Imaging Procedures and Findings
Lytic expansile lesion with bulby appearance and thining of cortex involving the right S1 ala is seen on CT scan . No evidence of periosteal reaction is detected. An axial T2WI shows an expansile lesion that has several fluidÃ¢??fluid levels (arrow). This is a typical appearance .
Aneurysmal bone cysts (ABCs) are virtually always aneurysmal or expansile . Aneurysmal bone cysts occur primarily in patients who are younger than age 30, although occasionally one will be encountered in older patients. Bony expansion and age of less than 30 years as fairly rigid guidelines and seldom miss the diagnosis of ABC. They often have fluidÃ¢??fluid levels on CT or MR , although this is a nonspecific finding, as many other lesions can have fluidÃ¢??fluid levels. ABCs typically present because of pain. They can occur anywhere in the skeleton, and there is no location that would make them more highly ranked in the differential diagnosis. As with osteoblastoma, they often occur in the posterior elements of the spine. There are apparently two types of ABCs: a primary type and a secondary type. The secondary type occurs in conjunction with another lesion or from trauma, whereas a primary ABC has no known cause or association with other lesions. Secondary ABCs have been said to occur with giant cell tumors, osteosarcomas, and almost any other lesion.
Aneurysmal Bone Cyst
Brant WE, Helms CA. Fundamentals of Diagnostic Radiology, 3rd edition. P1077-1078