DES and fibroma: However, the extrauterine adenomyoma needs to be differentiated from leiomyoma, gastrointestinal stromal tumor, schwannoma, granulosa cell tumor, fibroma, and similar conditions.[1,26] The smooth muscle of adenomyoma has characteristic positive expression of ER,[43] PR,[43] SMA,[43] and Desmin[43] and negative expression of CD117, Dog-1, CD34, and S100.