Spinal metastasis of nephroblastoma: Yes it exists.

Nephroblastoma or Wilms' tumor is the most common malignant tumor of the kidney in the pediatric population. Metastasis is caused by hematogenous spread. The most common localizations in decreasing order of frequency are lymph nodes, lungs, and liver. The bone is very rarely affected. According to the literature, bone metastases have been described in the iliac bone, skull, and mandible. The vertebral localization was described in 3 cases only, the first 1 in 2009, and the 2 others in 2015 . The goal of our work is to report a very rare case of metastatic vertebral localization of a Wilms' tumor in relapse after treatment; and thus to underline the potential for vertebral and intracanal involvement in nephroblastoma.