Malignant glomus tumor of kidney: the first reported case and review of literature.

Glomus tumors are mesenchymal neoplasms and are rarely seen in visceral organs like the kidney. Our patient presented with a metastatic, malignant, and highly aggressive glomus tumor in the kidney. In our extensive literature review, we did not come across even a single case of malignant glomus tumor arising in the kidney. We report the clinical presentation, radiologic, and pathological features of our case. Immunohistochemical findings that distinguish our case from other reported cases of glomus tumors arising from the kidney have been discussed. We have also reviewed the criteria for malignancy and other reported malignant glomus tumors.