tailieunhanh - Ebook Challenging cases in musculoskeletal imaging: Part 2

(BQ) Part 2 the book "Challenging cases in musculoskeletal imaging" presents the following contents: Shoulder girdle and thoracic cage, anterior chest wall as a whole, upper limb, lower limb, equivocal MRI findings, predominantly osteosclerotic changes,. | Shoulder Girdle and Thoracic Cage 5 Shoulder Girdle and Thoracic Cage Clavicle Case 78 Fig. Case description Referring physician orthopedist. Prior history and clinical question A 21-year-old man was examined radiologically for multiple injuries. A radiograph of the left clavicle showed a defect in the inferior border just lateral to the head of the clavicle the medial or sternal end of the clavicle . Before ordering biopsy the orthopedist wanted to know what the defect might represent. Radiologic Findings A semicircular defect is visible in the inferior border of the clavicle just lateral to the clavicular head see arrows in Fig. a . A subsequent whole-body bone scan Fig. b appears normal. Slightly increased uptake in the manubriosternal synchondrosis is considered appropriate for age. Location The defect is located at the attachment of the costoclavicular ligament. This was also seen in CT scans which are not reproduced here because the case can be solved without them see Assignment to a Possible Basic Entity below . A similar but very subtle finding was also noted on the contralateral side. Pathoanatomic Background of the Findings The tissue structure replacing the bone is not associated with increased bone turnover negative bone scan that is it does not incite a perifocal reaction and it does not form a matrix . bone cartilage ossifying connective tissue . Assignment to a Possible Basic Entity Normal variant or malformation Yes. The very fact that the defect was detected incidentally and was negative on the bone scan suggests a normal variant. When we consider its location see above it is reasonable to assume that we are dealing with a normal variant. Trauma inflammation tumor The negative history and negative bone scan exclude these basic entities from a realistic differential diagnosis. Synopsis and Discussion The apparent defect in the undersurface of the clavicle just lateral to the medial end of the clavicule clavicular head is called a