HSS What's the Diagnosis Case 95

What’s the Diagnosis – Case 95

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What’s the Diagnosis – Case 95

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What’s the Diagnosis – Case 95

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What’s the Diagnosis – Case 95

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What’s the Diagnosis – Case 95

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What’s the Diagnosis – Case 95

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Findings A mass is seen centered upon the ulnar cortex of the middle phalanx of the fourth digit. It has yielded indolent erosion of the cortex, with a thickened adjacent periosteal reaction. Contained within the lesion are punctate areas of calcification. On the MRI, it is fairly hyperintense on the more T2 weighted sequences with a multilobulated architecture. On the gradient echo sequence, subtle areas of low signal are seen within the mass suggestive of a matrix within the lesion.

What’s the Diagnosis – Case 95

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What’s the Diagnosis – Case 95

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Diagnosis: Juxtacortical chondroma Juxtacortical chondroma also referred to as periosteal chondroma or surface chondroma is a benign cartilage tumor typically found in young adults in the proximal humerus or femur in the metaphysis or occasionally as in this case of the finger. Typically they present with a thickened, or heaped up adjacent periosteal reaction. They then have similar characteristics to other benign cartilage tumors with punctate or ring and arc calcification on radiographs or CT and then prominent hyperintensity on more T2 weighted pulse sequences as well as a multilobulated architecture. Punctate areas of calcified cartilage matrix can be appreciated by areas of markedly low signal intensity/signal void on all pulse sequences Although a benign, process they are typically resected as they can be painful and there is frequently difficulty even on histology between differentiating a juxtacortical chondroma and a juxtacortical chondrosarcoma, which are typically low grade malignancies. A larger lesion of greater than 3 cm and more irregular or permeative characteristics to the lesion on imaging are typically more in favor of a malignant process.

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References Periosteal Chondroid Tumors:Radiologic Evaluation with Pathologic Correlation. P. Robinson, L. M. White, M. Sundaram, R. Kandel, J. Wunder, D. J. McDonald, C. Janney, R. S. Bell. AJR:177, November 2001 Juxta-cortical chondroma. Dr Yuranga Weerakkody,et al. Radiopaedia.org

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