Retroperitoneal malignant peripheral nerve sheath tumor associated with neurofibromatosis type 1: A case report

A female patient in her thirties was diagnosed with neurofibroma by left axillary skin biopsy, and neurofibromatosis type 1 (NF-1; von Recklinghausen disease) was suspected based on characteristic skin findings (cafe-au-lait spots) and her family history. In February X, the patient consulted a doctor for right thigh and back pain. An MRI and contrast CT showed a 13 cm retroperitoneal tumor, which was suspected to have originated from the L2 nerve root and to have invaded the spinal canal. The doctor referred the patient to our department for a surgical procedure. We consulted the Department of Orthopaedic Surgery and performed an MRI-guided biopsy, which suggested the possibility of a malignant peripheral nerve sheath tumor (MPNST). In June X, we resected the right retroperitoneal tumor following arterial embolization. Pathological results confirmed it to be an MPNST. The patient has not experienced any recurrence during the 10 months since the surgery. MPNSTs are extremely rare tumors and there is no standard treatment for them because of their rarity. We experienced a case of retroperitoneal MPNST and we herein report the features of this case and present some review of the literature.