Matrix Metalloproteinase 28-Bearing Microcystic Adnexal Carcinoma on the Back.

Although microcystic adnexal carcinoma (MAC) recurs and expands locally without metastases to the lymph nodes and other organs, its biological behavior remains unknown. In this report, a case of a giant MAC on the back treated with radical excision and curative radiation therapy and its characteristic dermoscopic findings are presented. In addition, immunohistochemical staining showed the expression of matrix metalloproteinase (MMP) 28 on the tumor cells and MMP12 and periostin in the stroma. The present case suggests the possible biological behaviors of MAC and might provide a possible target for the treatment of MAC in the future.