Metastatic lung tumor from hepatocellular carcinoma with tumor thrombus invasion in the pulmonary vein: a case report

Abstract

Background: Metastatic lung tumor with a tumor thrombus in the peripheral pulmonary vein is very rare. We present a case of a metastatic lung tumor from hepatocellular carcinoma (HCC) with tumor thrombus invasion in the pulmonary vein that was diagnosed preoperatively and underwent complete resection by segmentectomy.

Case presentation: A 77-year-old man underwent laparoscopic lateral segment hepatectomy for HCC eight years ago. Protein induced by vitamin K absence or antagonist-II remained elevated from two years ago. Contrast-enhanced chest computed-tomography (CT) showed a 27 mm nodule in the right apical segment (S1). He was pathologically diagnosed with a metastatic lung tumor from HCC via transbronchoscopic biopsy. We planned to perform right S1 segmentectomy. Before surgery, contrast-enhanced CT in the pulmonary vessels phase for three-dimensional reconstruction showed that the tumor extended into the adjusting peripheral pulmonary vein, and we diagnosed tumor thrombus invasion in V1a. The surgery was conducted under 3-port video-assisted thoracic surgery. First, V1 was ligated and cut. A1 and B1 were cut. The intersegmental plane was cut with mechanical staplers. Pathological examination revealed moderately-differentiated metastatic HCC with tumor thrombus invasions in many pulmonary veins, including V1a. No additional postoperative treatments were performed.

Conclusions: As malignant tumors tend to develop a tumor thrombus in the primary tumor, it might be necessary to perform contrast-enhanced CT in the pulmonary vessel phase to check for a tumor thrombus before the operation for metastatic lung tumors.

Keywords: Hepatocellular carcinoma; Metastatic lung tumor; Segmentectomy; Three-dimensional computed tomography; Tumor thrombus.

Fig. 1

Contrast-enhanced chest CT. Contrast-enhanced chest computed tomography (CT) showing a 27 mm nodule (white arrowhead) with mediastinal pleural invasion (white arrow) in the right apical segment

Fig. 2

Contrast-enhanced CT in the pulmonary vessels phase for 3D reconstruction. A Coronal view of contrast-enhanced computed tomography (CT) in the pulmonary vessel phase showing the tumor extended into the adjacent peripheral pulmonary vein (white arrowhead); B Three-dimensional (3D) reconstruction of the pulmonary vein showing tumor thrombus invasion in V1a (white arrowhead)

Fig. 3

Intraoperative finding after exposure of V1. V1 looks slightly-dilated (white arrowhead). Tumor thrombus in V1 is not recognized

Fig. 4

Resected specimen and micropathological findings. A Macroscopic findings of the resected specimen showing that the tumor invaded the pulmonary vein (white arrowhead). Cut end of the lung parenchyma (black arrowhead) is appropriately distant from the tumor (white arrow); B Micropathological examination revealing metastatic moderately differentiated hepatocellular carcinoma with tumor thrombus invasions in many pulmonary veins (white arrowhead)

Fig. 5

Comparison between standard contrast-enhance CT and contrast-enhanced CT in the pulmonary vessel phase. A Standard contrast-enhanced CT showing a tumor thrombus in the pulmonary vein (white arrowhead) could not be detected; B contrast-enhanced CT in the pulmonary vessel phase showing a tumor thrombus in the pulmonary vein (white arrowhead) was evident because of the difference from the other contrast-filled vessels