Malignant Gastrointestinal Neuroectodermal Tumors: Challenging Tumors With Diverse Morphology and Different Considerations for Differential Diagnosis.

Malignant gastrointestinal neuroectodermal tumors (MGNET) are extremely rare malignant mesenchymal tumors derived from ectodermal neural cells of the gastrointestinal tract that most commonly arise in the small intestine. Preoperative diagnosis is challenging owing to the lack of well-established imaging characteristics. However, MGNET exhibits distinctive histopathological features, immunohistochemical profiles, molecular genetic characteristics, and ultrastructural manifestations under electron microscopy. Due to its aggressive clinical course, early diagnosis and intervention are crucial for prolonging patient survival. Thus, it is imperative to differentiate MGNET from other tumor types such as malignant melanoma and neuroendocrine tumors. In this review, we explore the relationship between osteoclast-like giant cells and MGNET, as well as the association between EWSR1 gene rearrangement and MGNET, by reviewing published literature on MGNET. Our analysis covers clinical and imaging manifestations, histopathological characteristics, immunohistochemical features, electron microscopic findings, and molecular genetic profiles of MGNET patients. Furthermore, this review highlights key diagnostic differentiators between MGNET and other tumors, compares extragastrointestinal and intragastrointestinal MGNET manifestations, and summarizes recent research advances in MGNET treatment.