Spontaneous regression of lung metastases after transarterial chemoembolization for hepatocellular carcinoma

Abstract

Spontaneous regressions of primary and/or metastatic lesions have been rarely reported in hepatocellular carcinoma (HCC). Herein, we report the case of a 71-year-old man with HCC, focusing on shape changes of lung metastases over time. Lung metastasis of HCC was histologically diagnosed by percutaneous computed tomography (CT)-guided needle biopsy after the treatment of primary HCC lesion. Lung lesions had been observed on enhanced contrast computed tomography for >3 years without any local or systemic treatment for them. During this period, treatments including surgical procedure for relapsed bladder cancer and transarterial chemoembolization for HCC were performed. Metastatic lung lesions immediately regressed after these treatments. Therefore, accumulation of such cases may help elucidate spontaneous regression mechanisms in primary HCC or its lung metastases.

Keywords: Computed tomography-guided needle biopsy; Hepatocellular carcinoma; Lung metastases; Spontaneous regression; Transarterial chemoembolization.

Fig. 1

Chest CT images. The changes of CT images after referral our hospital are shown; 0 month (A), 4 months (B), 11 months (C), 17 months (D), 26 months (E), 35 months (F). The upper row shows left lower lobe (A-1 to F-1) and the lower row shows right lower lobe (A-2 to F-2). The arrows indicate the respective lesions. The shape and the size of 2 lung lesions on CT had been changed within 3 years. The maximum diameter: 11mm, 18 mm, 10 mm, 26 mm, none, 43 mm (Fig. A-1, B-1, C-1, D-1, E-1, F-1, respectively), 8 mm, 12mm, 8mm, 8mm, none, none (Fig. A-2, B-2, C-2, D-2, E-2, F-2, respectively). In addition, the concentration (CT value [Hounsfield Unit: HU]) inside the nodule was relatively uniform.

Fig. 2

Clinical course. The line graph shows the trend of PIVKA-II. In this graph, a to f correspond to the timing of the chest CT scan, and the images correspond to A to F in Figure 1. The timing of examinations and treatments were also indicated in the graph. The lung lesions regressed after TUR-BT and TACE with RFA, respectively. PIVKA-II fluctuated in accordance with the size of the lung lesions. After 35 months from the first referral to our hospital, he had hemoptysis and the left lung lesion appeared again. The lung lesion was diagnosed as metastases of hepatocellular carcinoma by percutaneous CT-guided biopsy. After Intensity-modulated Radiation therapy, hemoptysis has been disappeared and PIVKA-II has normalized. PIVKA-Ⅱ, protein induced by vitamin K absence/ antagonist-Ⅱ; TUR-BT, trans-urethral resection of bladder tumor; TACE, transarterial chemoembolization; RFA, radiofrequency ablation; FDG-PET, ¹⁸F-fluorodeoxyglucose positron emission tomography CT; IMRT, Intensity-modulated Radiation therapy

Fig. 3

¹⁸F-fluorodeoxyglucose positron emission tomography CT, bronchoscopy image and CT-guided lung biopsy. Thirty-five months later, ¹⁸F-fluorodeoxyglucose positron emission tomography CT showed a high degree of accumulation (SUV_max, 8.7-9.2) at the left lung lesion (A), and areas of suspected cancerous invasion to the bronchial mucosa was observed by bronchoscopy (B). Finally, CT-guided lung biopsy for the left mass was performed (C). A 18 G semi-automatic needle (MISSION, BARD Medical, Covington, GA, USA) was used to perform 2 biopsies in a prone position through the left back intercostal approach. The arrow indicates the tip of the biopsy needle, indicating that the biopsy needle has penetrated the left lung mass (circle).

Fig. 4

Histological findings. Hematoxylin-Eosin stain (× 200) of the lung mass obtained by CT guided lung biopsy showed trabecular pattern with 4+ cells thick; tumor cells with centrality, round-like shaped nucleus and abundant granular eosinophilic cytoplasm; common pattern in moderately differentiated HCC.