Analysis of human subcutaneous ossification.

<p>A) Surgically removed area of ossification from a 20 year old male AHO (−p/+) patient with a documented <i>GNAS</i> mutation. The site contained multiple irregular firm masses 0.5–4 cm in length with branching extensions from a central mass. B) Ossified lesion in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021755#pone-0021755-g001" target="_blank">Figure 1A</a> stained with hematoxylin and eosin. The lesion is composed of mature bone with frequent central bone marrow elements. Scale bar = 50 µm.