Glomangiomyoma (glomus tumor) of the kidney.

We report herein a case of glomus tumor arising in the kidney of a 55-year-old woman, which was found incidentally on a computed tomographic scan. Partial nephrectomy revealed a 2-cm encapsulated mass that was architecturally similar to glomus tumor. Immunohistochemistry showed positivity of tumor cells for vimentin and smooth muscle actin. On electron microscopy, cytoplasmic thin filaments and dense bodies were seen, confirming the smooth muscle nature of the tumor. Glomus tumors arising in visceral organs are rare, and those arising in kidney are exceedingly rare.