C-kit positive intraosseous myoepithelioma arising in rib: a case report

We describe a rare intraosseous myoepithelioma, arising in a rib. The patient was a 14-year-old female. The tumor, composed of epitheliod cells and plump spindle cells, was immunopositive for AE1/AE3, S-100 protein, HHF-35, desmin, smooth muscle actin (SMA), CD10, and c-kit, indicating a diagnosis of myoepithelioma. The tumor had invaded surrounding soft tissues, indicating a locally aggressive tumor. Positive staining for CD10 supported the diagnosis of myoepithelioma. To our knowledge, c-kit immunoreactivity has not been reported in intraosseous myoepithelioma. This form of myoepithelioma, arising in a rib and showing c-kit positivity, is very rare.