Imaging features of primary hepatic leiomyosarcoma: A case report and review of literature.

Primary hepatic leiomyosarcoma (PHL) is an extremely rare tumour. This tumour is difficult to diagnose by imaging examinations due to its rarity, and non-specific conventional imaging manifestations and clinical presentation. The present study reports the case of a 42-year-old male with PHL that was confirmed by histopathological and immunohistochemical examinations. Multimodal imaging examinations, including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT and digital subtraction angiography, were performed. The imaging manifestations were analysed and the associated literature was reviewed. The results found that no characteristic imaging appearance was present on ultrasound or plain CT scan. However, on unenhanced MRI, the tumours presented with a heterogeneous low signal density on T1-weighted imaging (WI) and a high signal density on T2WI and diffusion-WI. On gadopentetate dimeglumine enhanced MRI, the lesions were not enhanced during the arterial and portal venous phases; by contrast, these lesions were evidently enhanced during the 5-min delayed phase. Therefore, the delayed imaging of enhanced MRI is likely to be used to differentiate PHL from other hepatic tumours.