We describe two cases of benign nodules caused by sinusoidal dilatation with different hemodynamic statuses. Case 1 was a 50-year-old woman with a 1-cm nodule that showed a low density in the arterial phase of computed tomography. Pathologically, there were no atypical cells with sinusoidal dilatation, and immunostaining was negative for CD34. We speculated that sinusoidal dilatation was caused by congestion due to loss of frequency of the central vein. In contrast, case 2 was a 50-year-old woman with a 1.5-cm nodule that was highly stained in the arterial phase of computed tomography. Although she had a sinusoidal dilatation similar to that in case 1, immunostaining was positive for CD34. Sinusoidal dilatation was thought to be caused by hyperperfusion of arterial blood. Moreover, CD34 may be potentially useful for the differentiation of the hemodynamic status.
Keywords: Benign hepatic nodule; Focal nodular hyperplasia; Hemodynamics; Hepatic adenoma; Sinusoidal dilatation.