Dear Editor

In the year 2010, my colleagues and I published an article entitled \"The early detection of recurrence of malignant peripheral nerve sheath tumor by frequent magnetic resonance imaging[@B1]\" in the January 2010 issue of this journal. The presented patient showed two times of tumor recurrence around the primary site and gross total removals were achieved in both instances. In this article, I advocated the usefulness of frequent magnetic resonance imaging (MRI) at the primary focus in case of a malignant peripheral nerve sheath tumor (MPNST). It was recommended because it seems a local recurrence is favored rather thar the distant metastasis by MPNST. However, I want to share more information about this case thereafter.

After the third surgery, I had kept watching the patient\'s primary focus by using a MRI per every three to six months. Twenty-six months after the third surgery, another recurrence with any relevant symptoms was detected on MRI. The tumor was 5 mm in diameter and located within the intradural extramedullary space at the 6th thoracic spinal level. On the other hand, the original tumor and the previous two recurrences also were all detected at the 8th to 9th thoracic spine level. Actually the recurred tumor mass was well demarcated from surrounding tissue and a gross total removal was also achieved once more like it was at the previous three times of surgery. The tumor was proven as MPNST by pathologic examination. Neither radiation therapy, nor chemotherapy was given.

Sinse the fourth surgery four years passed and no more recurence was detected. The patient remained in a paraplegia since the initial occurrence of tumor. But besides of that the patient\'s general condition is still excellent. The observation will be conducted by MRI every six months.

![Magnetic resonance images show a well enhanced intradural and extramedullary located mass (white arrow) on 6th thoracic spine level.](jkns-55-387-g001){#F1}
