Bilateral Knee Pain in a 55-Year-Old Man

A 55-year-old man presents with bilateral knee pain. Radiographs of his legs and his chest are at right.[[{"type":"media","view_mode":"media_crop","fid":"27428","attributes":{"alt":"Gaucher disease","class":"media-image media-image-right","id":"media_crop_2568563221747","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"2663","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"float: right; width: 96px; height: 122px;","title":" ","typeof":"foaf:Image"}}]] (Click on the images to enlarge them.)

What do you notice?[[{"type":"media","view_mode":"media_crop","fid":"27429","attributes":{"alt":"Gaucher disease","class":"media-image media-image-right","id":"media_crop_6664934366627","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"2664","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"float: right; width: 84px; height: 87px;","title":" ","typeof":"foaf:Image"}}]]

Would you care to hazard a guess at the unusual diagnosis?

Click here for the case report and complete discussion.