The Prediction of Rare Clear Cell Carcinomas of the Liver via Pathological Component-Based Image Evaluation: A Case Report.

A 79-year-old woman with a history of hepatitis C was referred to our hospital for detailed examination of her hepatic mass. Computed tomography of the hepatic mass showed very weak ring enhancement only on portal and late-phase images. Ultrasound revealed a well-circumscribed mass with unchanged posterior echoes, a presumed thin capsule, and predominantly iso- to high internal echoes, including focal areas with slightly lower background echoes. Magnetic resonance imaging of the hepatic mass showed low signals on fat-suppressed T1-weighted images, high signals on fat-suppressed T2-weighted images, and faint ring enhancement through early-to-late-phase images on dynamic studies. These image findings led us to speculate that the tumor had both edematous fibrous components in its center and tumor cells with abundant cytoplasm and some kind of intracellular substances, i.e., possible clear cell hepatocellular carcinoma. We, therefore, resected the hepatic mass laparoscopically. The pathological study showed that the mass had a lobulated shape, edematous fibrous components in its central areas, and atypical cells with clear cytoplasm proliferating in both trabecular and solid fashions. Immunostaining of the tumor revealed hepatocyte, arginase 1, CK20, CD10, CA9, and TFE3 negativity, along with AE1/AE3 and CK7 positivity, leading to the diagnosis of clear cell carcinoma of the liver. The patient recovered uneventfully and was discharged on the sixth postoperative day. Diagnostic physicians should note that pathological component-based image evaluation can predict histological characteristics even for very rare clear cell carcinomas of the liver.