[Imaging findings in XXXX ].

@entity1 @entity5 @entity4 @entity79 @entity84 @entity690
OBJECTIVE: To describe the imaging findings, with special emphasis on the magnetic resonance (MRI) findings and the clinical and radiological presentation of @entity84 . MATERIAL AND METHODS: This is a retrospective study of 18 @entity1 (12 @entity1 and 6 @entity1 ; mean age, 19 years) diagnosed with @entity84 . All @entity1 underwent plain-film radiography, 16 underwent MRI, and 12 underwent CT. We evaluated the location, size, pattern of @entity79 , @entity5 matrix, periosteal reaction, signal intensity on T1- and T2-weighted sequences, and the presence of bone or soft-tissue @entity4 . RESULTS: The lesions were located in the distal femur (n = 6), proximal humerus (n = 5), ilium (n = 3), proximal femur, proximal tibia, patella, and scapula. Mean lesion diameter was 3.5 cm (range: 1 to 10 cm). A calcified @entity5 matrix was observed in 50% of the cases and a periosteal reaction was seen in 44%. MRI showed a homogeneous intramedullary lesion that was isointense to muscle on T1-weighted sequences. On T2-weighted sequences, the signal intensity was more variable and was always heterogeneous. Perilesional @entity4 affecting the bone and/or soft tissues was demonstrated in 94% of the cases and is a distinctive finding for this @entity5 . CONCLUSIONS: @entity84 should be suspected in a young @entity1 with an @entity690 . It is usually a localized lesion that often shows @entity5 matrix and periosteal reaction. CT and especially MRI are useful in the study of the extension of the lesion and in the characterization of this @entity5 . @entity84 typically shows @entity4 , periosteal reaction, and soft-tissue @entity4 .
