Solid variant of aneurysmal bone cysts in long tubular bones: giant cell reparative granuloma.
OBJECTIVE
The purpose of this study was to determine the age distribution, location, and imaging features of histologically proven solid variants of aneurysmal bone cysts in long tubular bones.


METHODS
We performed a retrospective review of imaging studies of histologically proven solid aneurysmal bone cysts in long bones between 1961 and 2001. There were 30 cases comprising 29 radiographic, six CT, and eight MR imaging examinations. The lesions were evaluated for bone involved, location within a long bone, matrix, size, soft-tissue mass, and MR imaging characteristics. The imaging findings were correlated with the histologic findings.


RESULTS
The patients were 17 females and 13 males ranging in age from 2 to 58 years (mean, 18 years). The bones involved were the femur (n = 10), the ulna (n = 7), the tibia (n = 7), the humerus (n = 2), the radius (n = 2), and the fibula (n = 2). The lesions were five juxtaarticular, 13 metaphyseal, one diametaphyseal, and 11 diaphyseal. The location was eccentric in 20 cases, of which two were intracortical and two periosteal, and central in 10. Lesion size varied between 1 and 7 cm. Thirty-three percent of lesions were nonaneurysmal. Four lesions were mineralized. A soft-tissue mass was present in four cases. Four lesions showed a permeative-lytic pattern simulating a malignant process. Unusual findings included periosteal reaction and development of a solid aneurysmal bone cyst in a preexisting fracture. MR imaging showed solid elements in all cases and pronounced edema in 50% of cases.


CONCLUSIONS
Solid aneurysmal bone cyst is a reactive nonneoplastic bone lesion with varied imaging characteristics; one third of lesions are nonaneurysmal.
Ilaslan
Hakan
H
Department of Radiology, Mayo Clinic, Ch2-290, 200 First St., S.W., Rochester, MN 55905, USA.
Sundaram
Murali
M
Unni
K Krishnan
KK
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D017824:Bone Cysts, Aneurysmal / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000473:pathology*; D005360:Fibula / Q000000981:diagnostic imaging* / Q000473:pathology*; D006101:Granuloma, Giant Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011884:Radius / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies; D013977:Tibia / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014457:Ulna / Q000000981:diagnostic imaging* / Q000473:pathology*