Recently, LCAs with typical backgrounds of the patients are diagnosed by radiological findings without pathological findings due to the progress of diagnostic imaging techniques. A typical LCA shows low density or isodensity on plain computed tomography, presents a homogenous contrasting effect on arterial phase and does not show an apparent wash out on delayed phase. A typical LCA in magnetic resonance imaging shows almost the same signal intensity as the surrounding parenchyma on T1 and T2 and shows high intensity on fat suppression T2. However, LCA often presents difficulties in a differential diagnosis with well-differentiated HCC, especially without the typical backgrounds of the patients.
A research article to be published on March 14, 2009 in the World Journal of Gastroenterology reports an extremely rare case of LCA. The research team led by Prof. Shimosegawa from the Division of Gastroenterology, Tohoku University reported a case of LCA found in a 40-year-old woman without a typical history in which the sequential alteration of the radiological findings suggested well-differentiated HCC.
A liver tumor 35 mm in diameter was found incidentally in a woman, which showed a homogenous enhancement in the arterial phase and almost the same enhancement as the surrounding liver parenchyma in the delayed phase of CT. The tumor was found to contain fat on MRI. However, radiological findings altered, which caused to suspect that a well-differentiated HCC containing fat was becoming dedifferentiated. Partial hepatectomy was performed and the pathological findings showed the typical findings of LCA. Diagnosis of LCA only by radiological findings is difficult in patients without backgrounds such as a history of receiving contraceptives or glycogen-storage disease.