Malignant triton tumor in the abdominal wall: A case report

Background: Malignant triton tumors (MTTs) comprise a subgroup of malignant peripheral nerve sheath tumors (MPNSTs) that exhibits rhabdomyosarcomatous differentiation and follow an aggressive course. MTTs are primarily located along peripheral nerves. Cases of MTTs in the abdominal wall have not been reported. MTT has a poorer prognosis than classic MPNSTs, and accurate diagnosis necessitates a keen understanding of the clinical history and knowledge of its differential diagnosis intricacies. Treatment for MTTs mirrors that for MPNSTs and is predominantly surgical.

Case summary: A 49-year-old woman presented with a subcutaneous mass in her lower abdominal wall and a pre-existing surgical scar that had grown slowly over 3-4 months before the consultation. She had previously undergone radical hysterectomy and concurrent chemo-radiotherapy for cervical cancer approximately 5 years prior to the consultation. Abdominal computed tomography (CT) showed a 1.3 cm midline mass in the lower abdomen with infiltration into the rectus abdominis muscle. There was no sign of metastasis (T1N0M0). An incisional biopsy identified sporadic MTT of the lower abdomen. A comprehensive surgical excision with a 3 cm margin inclusive of the peritoneum was executed. Subsequently, the general surgeon utilized an approach akin to the open peritoneal onlay mesh technique. The patient underwent additional treatment with an excision shaped as a mini-abdominoplasty for the skin defect. No complications arose, and annual follow-up CTs did not show signs of recurrence or metastasis.

Conclusion: An abdominal MTT was efficaciously treated with extensive excision and abdominal wall reconstruction, eliminating the need for postoperative radiotherapy.