Diagnostic value of imaging modalities in primary squamous cell carcinoma of the liver.

Primary squamous cell carcinoma of the liver (PSCCL) is rare. PSCCL's lack of specific clinical manifestations and laboratory tests necessitate preoperative diagnosis via imaging examination. Conventional ultrasound (US) demonstrates a mass with mixed echogenicity, and contrast-enhanced US shows a circular pattern of "fast forward, fast backward or slow backward, high enhancement." Enhanced computed tomography (CT) showed enhancement in the center or edge of the lesion, and the density of the enhanced lesion was lower than that of the liver tissue in the same layer. Positron emission tomography-CT demonstrates an inhomogeneous low-density mass with increased 18F-FDG metabolism. Magnetic resonance imaging shows low signal intensity on T1-weighed images (T1WI) and high signal on T2-weighed images (T2WI). By summarizing the imaging characteristics of PSCCL, this review aims to improve clinicians' understanding of PSCCL and its diagnosis.