Unusual high signal intensity on MR images in a patient with multiple tendinous xanthomas.

The MR features of a 57-year-old man with multiple tendinous xanthomas are reported. The lesions of the peroneus longus tendons and the Achilles tendons showed diffuse reticulated pattern, which is the typical MR finding of tendinous xanthomas. However, the lesions of the patellar tendons showed no diffuse pattern and contained focal regions of high signal intensity on T 1-weighted images suggesting the deposition of triglycerides. The regions showed high signal intensity on T 2-weighted images and moderate enhancement on contrast-enhanced T 1-weighted images suggesting the presence of associated inflammation.