Malignant triton tumor below the peritoneal reflection
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
Malignant triton tumor (MTT) is a rare subtype of malignant peripheral nerve sheath tumors (MPNSTs) histologically defined by rhabdomyoblastic differentiation. MTTs are primarily found in the head, neck, extremities, and trunk, but rare cases of MTT within the buttock, the mediastinum, and the retroperitoneum have also been documented.

A healthy 47-year-old male with past medical history significant only for hypertension and nephrolithiasis with right flank pain radiating to the pubis, hematuria, hard stool with straining, and fifteen-pound weight loss over 6 months. On physical examination, multiple café au lait spots, small neurofibromas on his trunk and arms and axillary and inguinal freckling were observed. On CT scan, he was found to have a 10.1-cm soft tissue mass in the right hemipelvis and a nephroureteral stent with a 3-mm stone in the proximal right ureter. Further history revealed the patient had a known pelvic mass discovered on CT approximately 10 years prior.

During hospitalization, colonoscopy with biopsy of the mass and partial polypectomy of a large benign-appearing polyp in the ascending colon revealed spindle cells and a tubular adenoma with intramucosal adenocarcinoma, respectively.

Days later, he returned to the emergency department with worsening right flank pain. He was taken to the operating room for mass resection. Rectal examination revealed a palpable large pelvic mass displacing but not invading the rectum. Initial laparoscopy revealed no abnormality in the small or large intestine, omentum, liver or spleen. Robotic approach was utilized to enter the mesorectal space posterior to the rectum, taking care to preserve the ureters and hypogastric nerves. Robotic dissection continued to open the anterior peritoneal reflection, where a large tumor was noted abutting the right side of the rectum, pelvic bone and obturator canal. The mass was carefully separated from these structures using sharp dissection and electrocautery. The urology team then continued dissection, freeing the mass from the prostate, bladder and right seminal vesicle. The tumor was removed through a Pfannenstiel incision covered by a GelPort. The incisions were closed. The patient was extubated in the OR, having tolerated the procedure well. His postoperative course was only remarkable for a brief period of urinary retention, which resolved spontaneously. He was discharged home on a postoperative day 3 with scheduled follow-up appointments with urology and colorectal surgery.