Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare a rare subtype of hepatocellular carcinoma. The IMbrave150 trial demonstrated that atezolizumab and bevacizumab therapy (ABT) has better treatment outcomes than sorafenib for advanced HCC. However, since patients with known FLHCC were excluded from this trial, the effects of ABT on FLHCC remain unknown. We report the first case of ABT for advanced FLHCC followed by hepatectomy presenting pseudoprogression of lymph node (LN) metastases which was pathologically proven after surgery. The patient was a 30-year-old man with advanced FLHCC and multiple LN metastases behind the pancreatic head, and ABT was introduced. After four courses of treatment, CT indicated a minor decrease in the intratumor vascularity of the liver tumor. However, the size of metastatic LNs increased. Subsequently, the patient presented with bloody stool, and colonoscopy revealed immune-related colitis caused by atezolizumab. Therefore, the fifth course was canceled. A right hemihepatectomy following percutaneous transhepatic portal vein embolization (PTPE) was performed to increase the future liver remnant volume. After PTPE, dynamic CT revealed an objective response to ABT; SD in RECIST 1.1 (7% increase in the LN size and no change of liver tumor), and PR in modified RECIST (47% decrease in the intratumor vascularity of the liver tumor and LNs). Three weeks after PTPE, right hemihepatectomy plus nodal dissection was successfully performed. Pathological findings revealed that approximately 60%–70% of the liver tumor and 70%–80% of the metastatic LNs were necrotic, indicating a good response to ABT. The increasing size of metastatic LNs that occurred during the treatment course was deemed pseudoprogression. Pseudoprogression can be found in patients with solid malignancies treated with immune checkpoint inhibitors, however, rarely occurs in HCC. The first response to metastatic LNs was observed 20 weeks after ABT initiation combined with an increase in nodal volume and a decrease in vascularity. In the updated data of the IMbrave150 trial, 19% of the first responses occurred after week 24. Physicians should consider that ABT may also be effective in FLHCC and may cause pseudoprogression before determining a treatment strategy.


中文翻译：

---

Atezolizumab 和贝伐珠单抗联合治疗和序贯转换肝切除术治疗出现假性进展的晚期纤维板层肝细胞癌

纤维板层肝细胞癌（FLHCC）是一种罕见的肝细胞癌亚型。IMbrave150 试验表明，对于晚期 HCC，阿特朱单抗和贝伐单抗疗法 (ABT) 的治疗效果优于索拉非尼。然而，由于已知患有 FLHCC 的患者被排除在该试验之外，因此 ABT 对 FLHCC 的影响仍不清楚。我们报告了第一例针对晚期 FLHCC 进行 ABT 治疗，随后进行肝切除术，出现淋巴结 (LN) 转移假性进展的病例，这在手术后得到了病理学证实。该患者是一名 30 岁男性，患有晚期 FLHCC，胰头后有多发淋巴结转移，采用 ABT。四个疗程后，CT显示肝肿瘤瘤内血管分布略有减少。然而，转移性淋巴结的大小增加了。随后，该患者出现血便，结肠镜检查显示阿特珠单抗引起的免疫相关性结肠炎。因此，第五门课程被取消。经皮肝穿刺门静脉栓塞术（PTPE）后进行右半肝切除术，以增加未来的肝脏残余体积。PTPE 后，动态 CT 显示对 ABT 的客观反应；RECIST 1.1 中的 SD（LN 大小增加 7%，肝肿瘤没有变化），改良 RECIST 中的 PR（肝肿瘤和 LN 的肿瘤内血管分布减少 47%）。PTPE 三周后，成功进行右半肝切除加淋巴结清扫。病理结果显示，大约60%~70%的肝脏肿瘤和70%~80%的转移性淋巴结坏死，表明对ABT有良好的反应。治疗过程中发生的转移性淋巴结增大被认为是假性进展。在接受免疫检查点抑制剂治疗的实体恶性肿瘤患者中可以发现假性进展，但在 HCC 中很少发生。ABT 开始 20 周后观察到对转移性淋巴结的首次反应，并伴有淋巴结体积增加和血管分布减少。在 IMbrave150 试验的更新数据中，19% 的首次缓解发生在第 24 周后。医生在确定治疗策略之前应考虑到 ABT 也可能对 FLHCC 有效，但可能会导致假性进展。ABT 开始 20 周后观察到对转移性淋巴结的首次反应，并伴有淋巴结体积增加和血管分布减少。在 IMbrave150 试验的更新数据中，19% 的首次缓解发生在第 24 周后。医生在确定治疗策略之前应考虑到 ABT 也可能对 FLHCC 有效，但可能会导致假性进展。ABT 开始 20 周后观察到对转移性淋巴结的首次反应，并伴有淋巴结体积增加和血管分布减少。在 IMbrave150 试验的更新数据中，19% 的首次缓解发生在第 24 周后。医生在确定治疗策略之前应考虑到 ABT 也可能对 FLHCC 有效，但可能会导致假性进展。