Computed Tomography Imaging Features of Malignant “Triton” Tumor for Its Clinical Diagnosis: Report of Two Cases

Abstract Background: malignant triton tumors (MTTs) are an extremely rare subtype of malignant periphery nerve sheave tumors (MPNSTs). Clinical diagnosis of MTTs is difficult before surgery due to its low incidence and the lack of knowledge. Therefore, to describe and summarize the computed tomography (CT) imaging characteristics of malignant triton tumors (MTTs) is of great assistance for early and preoperative diagnosis.Case presentation: Two case reports were closely observed in our hospital, with the presumptive diagnosis of MTT by CT scan examination before surgery. The diagnosis of MTT was eventually confirmed by immunochemical (IHC) assay, which verified speculation of CT scans. Huge, irregular, well-circumscribed lobulated mass-like shadows can be observed from these patients by CT scans. Besides, heterogeneity of density within the body of tumor was well-established by CT scans, together with linear septum. Meanwhile, CT scans demonstrated that calcifications were remarkable at the margin of tumor body. Conclusions: Some CT image features from two cases admitted to our hospital were presented as a reference for the preoperative diagnosis of MTTs: (i) enormity of mass-like shadow; (ii) presence of well-circumscribed lobulated shape; (iii) septum within the well-defined mass accompanied with hemorrhage, necrosis and cystic changes as well as calcification, especially within neurofibromatosis type 1 (NF-1) patients.