OBJECTIVE: The purpose of our study was to determine the prevalence of incidental enchondromas on routine MR knee imaging. MATERIALS AND METHODS: We retrospectively reviewed 449 consecutive routine knee MR examinations for the presence of enchondromas. MRI was considered positive when a focal geographic area of lobular marrow replacement (nonsubchondral) was identified on T1 weighting and high signal intensity was seen on T2 weighting. Patients with enchondromas were further evaluated for demographics; lesion site, size, and relationship to the physeal plate; aggressive imaging features described with chondrosarcoma; concurrent internal derangement; and study indication. RESULTS: The prevalence of incidental enchondromas was 2.9% on routine knee MR examinations. The prevalence was highest in the distal femur (2.0%), followed by the proximal tibia (0.7%) and the proximal fibula (0.2%). The average lesion size was 1.9 x 1.2 x 1.3 cm (57% of lesions were < 1 cm). Most lesions were located in the metaphysis (71%) or diaphysis (21%). Enchondromas were within 1.5 cm of the physeal plate in 72% of cases. No aggressive imaging features to suggest chondrosarcoma were seen. All patients had evidence of internal derangement as the cause of symptoms and the request for imaging. CONCLUSION: Incidental enchondromas can be identified on 2.9% of routine MR knee examinations, most frequently in the distal femur (2.0%). This significant prevalence is much higher than in an autopsy series (0.2%), likely reflecting the increased sensitivity of MRI for detecting small lesions, and is important to recognize to avoid confusion with other pathologic entities.
OBJECTIVE: The purpose of our study was to determine the prevalence of incidental enchondromas on routine MR knee imaging. MATERIALS AND METHODS: We retrospectively reviewed 449 consecutive routine knee MR examinations for the presence of enchondromas. MRI was considered positive when a focal geographic area of lobular marrow replacement (nonsubchondral) was identified on T1 weighting and high signal intensity was seen on T2 weighting. Patients with enchondromas were further evaluated for demographics; lesion site, size, and relationship to the physeal plate; aggressive imaging features described with chondrosarcoma; concurrent internal derangement; and study indication. RESULTS: The prevalence of incidental enchondromas was 2.9% on routine knee MR examinations. The prevalence was highest in the distal femur (2.0%), followed by the proximal tibia (0.7%) and the proximal fibula (0.2%). The average lesion size was 1.9 x 1.2 x 1.3 cm (57% of lesions were < 1 cm). Most lesions were located in the metaphysis (71%) or diaphysis (21%). Enchondromas were within 1.5 cm of the physeal plate in 72% of cases. No aggressive imaging features to suggest chondrosarcoma were seen. All patients had evidence of internal derangement as the cause of symptoms and the request for imaging. CONCLUSION: Incidental enchondromas can be identified on 2.9% of routine MR knee examinations, most frequently in the distal femur (2.0%). This significant prevalence is much higher than in an autopsy series (0.2%), likely reflecting the increased sensitivity of MRI for detecting small lesions, and is important to recognize to avoid confusion with other pathologic entities.
Authors: Jacob L Jaremko; Peter J MacMahon; Martin Torriani; Vanessa L Merker; Victor F Mautner; Scott R Plotkin; Miriam A Bredella Journal: Skeletal Radiol Date: 2011-12-07 Impact factor: 2.199
Authors: Guillaume Bierry; Darcy A Kerr; G Petur Nielsen; Andrew E Rosenberg; Ambrose J Huang; Martin Torriani; Miriam A Bredella Journal: Skeletal Radiol Date: 2012-02-27 Impact factor: 2.199
Authors: Catharina S Lisson; Christoph G Lisson; Kerstin Flosdorf; Regine Mayer-Steinacker; Markus Schultheiss; Alexandra von Baer; Thomas F E Barth; Ambros J Beer; Matthias Baumhauer; Reinhard Meier; Meinrad Beer; Stefan A Schmidt Journal: Eur Radiol Date: 2017-09-07 Impact factor: 5.315
Authors: Kimmie L Bui; Hakan Ilaslan; Thomas W Bauer; Steven A Lietman; Michael J Joyce; Murali Sundaram Journal: Skeletal Radiol Date: 2009-03-11 Impact factor: 2.199