Recurrent extrarenal Teratoid Wilms tumor in sacrococcygeal region of children after initial surgery: A rare case.

Teratoid Wilms tumor is a very rare tumor, about 70 cases have been reported worldwide. Extrarenal teratoid Wilms tumor is even less common. We reported a child with sacrococcygeal teratoid Wilms tumor who was diagnosed with teratoma at the time of the initial operation and relapsed shortly after the operation; we followed up for nearly two years after the second operation with no tumor recurrence or metastasis. This case tells clinicians that the diagnosis of extrarenal teratoid Wilms tumor needs to be careful, and although the prognosis of the disease is good, the premise is complete surgical resection.