肝胆膵：肝の非多血性病変，肝細胞癌の治療後，胆道結石，膵嚢胞

Management of hepato-biliary-pancreatic lesions：hepatic lesions without hyperenhancement, hepatocellular carcinomas after some therapies, cholelithiasis, and pancreatic cysts

肝細胞癌の多段階発癌の過程において血行支配が変化することが知られている。異形結節で正常門脈と正常肝動脈が減少し始める一方，異常動脈とcapillarizationが次第に増加する。早期肝癌では動脈血流は周辺肝とほぼ同等となり，高分化から中分化型肝細胞癌にかけて動脈血流は著増する^1）。よって，いわゆる前癌～早期病変としての非多血性病変は異形結節～早期肝癌に相当すると考えられる。

Hepatic lesions without hyperenhancement generally correspond to atypical nodules to early-stage hepatocellular carcinoma, but caution should be exercised because advanced liver cancer is also included.

Post-treatment surveillance of hepatocellular carcinoma is just as important as surveillance for recurrence and requires close follow-up as in the very high-risk group. Although Gd-EOB-DTPA contrast-enhanced MRI is often useful in the evaluation of recurrence, other modalities are also used for follow-up in view of the cost and time required for the examination. As a rule, cholecystolithiasis is treated when symptomatic, while follow-up is the treatment of choice when asymptomatic. For choledocholithiasis and hepatolithiasis, treatment is indicated even if the patient is asymptomatic from the viewpoint of complications and carcinogenesis. Pancreatic cysts include a variety of lesions ranging from benign to potentially malignant. Comorbid pancreatic cancers have also been reported. Therefore, follow-up should be based on the risk of the lesion.