title: A rare case of retroperitoneal malignant Triton tumor invading renal vein and small intestine.
abstract: BACKGROUND
  Malignant Triton tumor is a very rare malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation. Most of those tumors occur in patients with von Recklinghausen's disease or as a late complication of irradiation and commonly seen in the head, neck, extremities and trunk.
  
  
  METHODS
  We reported retroperitoneal malignant Triton tumor in a 57-year-old female patient. Skin lesions were not present, and there was no family history of neurofibromatosis or previous irradiation. The presented case is one of a few recorded in the specialized literature that occurs in the retroperitoneal space in sporadic form. In this case, tumor consisted of a multilobular mass was in close relation with the abdominal aorta and inferior vena cava and involved the renal vein with gross invasion of the small intestine. The patient underwent total resection of the tumor and left nefrectomy was performed. The small intestine 10 cm in length was also resected and end-to-end anastomosis was conducted. The postoperative course was uneventful and the patient was discharged from the hospital ten days after the surgery.
  
  
  CONCLUSIONS
  Diagnostically, it is crucial to recognize this uncommon histological variant because malignant Triton tumor has a worse prognosis than classic malignant peripheral nerve sheath tumor does. The use of the immunohistochemistry is essential in making the correct diagnosis. Only appropriate pathological evaluation supported by immunostaining with S-100 protein and desmin confirmed the diagnosis. Aggressive surgical management treatment improves the prognosis of such cases with adjuvant radiotherapy.
authors.affiliation: Institute of Pathology, Faculty of Medicine, University of Nis, Nis, Serbia. zaklinamijovic@gmail.com
authors.forename: Zaklina
authors.initials: Z
authors.lastname: Mijović
authors.forename: Dragan
authors.initials: D
authors.lastname: Mihailović
authors.forename: Nikola
authors.initials: N
authors.lastname: Zivković
authors.forename: Milos
authors.initials: M
authors.lastname: Kostov
authors.forename: Sladjana
authors.initials: S
authors.lastname: Zivković
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Stojanović
mesh_terms: D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018317:Nerve Sheath Neoplasms / Q000473:pathology*; D012082:Renal Veins / Q000473:pathology*; D012186:Retroperitoneal Neoplasms / Q000473:pathology*