Background: Malignant peripheral nerve sheath tumor (MPNST) is a rare and highly aggressive soft tissue tumor. The appearance of MPNSTs is often similar to that of other soft tissue tumors, making diagnosis difficult. Additionally, the lack of specific criteria and guidelines for establishing the diagnosis of MPNST makes it very challenging to diagnose. Radiological examinations can help confirm the diagnosis. Objective: In this case report, we present multimodal radiological findings used in diagnosing MPNST. Case presentation: A 40-year-old woman presented with complaints of a lump on the left side of her neck that had been increasing in size for 1.5 years. Ultrasound examination revealed a mass with malignant characteristics in the left colli, extending from the submandibular to the left supraclavicular area, suspected of infiltrating the surrounding muscles. The contrast-enhanced MRI showed a T1-weighted isointense mass with hyperintense T2-weighted signals, which intensified after contrast administration. The mass also showed necrotic components and diffusion restriction, with the lesion predominantly located in the visceral space of the left side of the neck, accompanied by obliteration of the left internal jugular vein. Immunohistochemistry results from the biopsy showed a malignant tumor in the peripheral nerve sheath, grade 1. These findings support the diagnosis of MPNST. Conclusion: Therefore, understanding the features and characteristics of MPNST findings in various radiological modalities is crucial for accurate diagnosis. Early identification through radiological examinations can facilitate prompt management and improved patient outcomes. © The Author(s) 2025.