Abstract

Malignant glomus tumor is a rare neoplasm arising from the glomus body, comprising categories of locally infiltrative glomus tumor, sarcoma arising in benign glomus tumor and de novo glomangiosarcoma. We report one case of locally infiltrative glomus tumor arising in nail bed of the right thumb of a 50 year-old woman. The tumor showed the architectural features of glomus tumor but cytologically bizarre, pleomorphic features without mitosis and infiltrative growth pattern to adjacent connective tissue and nerve. Immunohistochemical results were consistent with glomus tumor. This category of malignant glomus tumor must be distinguished from other round cell tumors because of its good prognosis.

• Keywords: Infiltrative glomus tumor;Subungual;