Malignant Peripheral Nerve Sheath Tumor in the Retroperitoneum Not Associated With the Renal or Perirenal Parenchyma: A Case Report

The occurrence of an isolated malignant peripheral nerve sheath tumor (MPNST) in the retroperitoneum, unassociated with the kidney capsule, is exceedingly rare, often presenting with an insidious onset of non-specific and misleading symptoms, primarily characterized by lower back pain. We present the case of a patient with a malignant peripheral nerve sheath tumor (MPNST), without neurofibromatosis with nonspecific localization in the retroperitoneum in front of vena cava inferior non associated with the kidney. A 62-years-old male patient was referred due to the presence of an abdominal tumor without accompanying pain. Computed tomography identified a substantial soft tissue retroperitoneal tumor situated anterior to the inferior vena cava. A total resection was performed. The pathological testing verified the existence of a malignant peripheral nerve sheath tumor. The patient received additional treatment through radiotherapy and chemotherapy. This is the inaugural reported case of malignant peripheral nerve sheath tumor in the retroperitoneum without neurofibromatosis, unassociated with renal or perirenal parenchyma. We recommend incorporating malignant peripheral nerve sheath tumor into the differential diagnosis of abdominal masses.