Malignant triton tumor of the kidney in a child: A case report

• Published in: International journal of surgery case reports 2021-08, Vol.85, p.106252-106252, Article 106252
• Main Authors: Bins, Rafael Bittencourt, Pinzon, Carlos Eduardo, da Silva Pereira, Leonardo Dantas, Bertuol, Marina, Isolan, Paola Maria Brolin Santis, Takamatu, Eliziane Emy
• Format: Article
• Language: English
• Subjects: Case Report; Malignant peripheral nerve sheath tumors; Malignant triton tumor; Rhabdomyosarcomatous differentiation
• ISSN: 2210-2612; 2210-2612
• DOI: 10.1016/j.ijscr.2021.106252

Malignant triton tumor (MTT) is an extremely rare variant of the malignant peripheral nerve sheath tumors (MPNSTs) with rhabdomyosarcomatous differentiation, which was first described in 1932 by Mason. MTT affects, in most cases, patients under 35 years of age, and it is usually manifested as a mass that may or not be painful. However, the incidence in pediatric patients is atypical. This tumor presents an aggressive course and limited survival rate, and the prognosis is different between individuals with or without a concomitant diagnosis of neurofibromatosis type 1 (NF1). Currently, the recommended treatment is surgical resection, and adjuvant chemotherapy and radiotherapy, but its efficacy is not yet clear. A 13-year-old female patient was referred to the pediatric oncology service due to the presence of an abdominal mass and weight loss, initially diagnosed with Wilms' tumor. After extensive investigation, surgical resection, and immunohistopathological evaluation, the diagnosis of malignant triton tumor was confirmed. The patient also underwent cycles of chemotherapy after resection, and is currently awaiting immunotherapy. Malignant triton tumor is extremely rare and difficult to diagnose, especially in children or young people, age groups in which the incidence of the disease is even lower. This may be the reason it is rarely suspected, and it was a great challenge for the clinical care team. It is essential to consider and investigate this possibility of differential diagnosis, as patients diagnosed with this malignant tumor have a low survival rate and poor prognosis. •Malignant triton tumor (MTT) is an extremely rare histological subtype of MPNSTs.•MTT is an MPNST with rhabdomyosarcomatous differentiation.•MTT is an extremely rare type of neoplasia, especially in pediatric patients.•The kidney is an uncommon growth site of MTT.•MTT presents a complex anatomopathological and immunohistochemical diagnosis.