A 70‐year‐old man undergoing treatment for immunoglobulin G4‐related disease developed a liver mass on computed tomography during routine imaging examination. The tumor was located in the hepatic S1/4 region, was 38 mm in size, and showed arterial enhancement on dynamic contrast‐enhanced computed tomography. We performed a liver biopsy and diagnosed moderately differentiated hepatocellular carcinoma. The patient underwent proton beam therapy. The tumor remained unchanged but enlarged after 4 years. The patient was diagnosed with hepatocellular carcinoma recurrence and received hepatic arterial chemoembolization. However, 1 year later, the patient developed jaundice, and the liver tumor grew in size. Unfortunately, the patient passed away. Autopsy revealed that the tumor consisted of spindle‐shaped cells exhibiting nuclear atypia and a fission pattern and tested positive for α‐smooth muscle actin and vimentin. No hepatocellular carcinoma components were observed, and the patient was pathologically diagnosed with hepatic leiomyosarcoma. Next‐generation sequencing revealed somatic mutations in CACNA2D4, CTNNB1, DOCK5, IPO8, MTMR1, PABPC5, SEMA6D, and ZFP36L1. Based on the genetic mutation, sarcomatoid hepatocarcinoma was the most likely pathogenesis in this case. This mutation is indicative of the transition from sarcomatoid hepatocarcinoma to hepatic leiomyosarcoma.

中文翻译：

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肝细胞癌治疗后侵袭性肝平滑肌肉瘤病例的基因组分析

一名 70 岁男性正在接受免疫球蛋白 G4 相关疾病的治疗，在常规影像学检查中，计算机断层扫描发现肝脏肿块。肿瘤位于肝脏S1/4区，大小为38毫米，动态增强计算机断层扫描显示动脉强化。我们进行了肝活检并诊断为中分化肝细胞癌。患者接受了质子束治疗。4年后，肿瘤没有变化，但增大了。患者被诊断为肝细胞癌复发并接受肝动脉化疗栓塞术。然而一年后，患者出现黄疸，肝肿瘤增大。不幸的是，病人去世了。尸检显示，肿瘤由梭形细胞组成，表现出核异型性和裂变模式，α-平滑肌肌动蛋白和波形蛋白检测呈阳性。未观察到肝细胞癌成分，病理诊断为肝平滑肌肉瘤。下一代测序揭示了体细胞突变CACNA2D4,CTNNB1,底座5,首次公开募股8,MTMR1,PABPC5,SEMA6D， 和ZFP36L1。根据基因突变，肉瘤样肝癌是该病例最有可能的发病机制。该突变表明从肉瘤样肝癌向肝平滑肌肉瘤的转变。