Percutaneous transcatheter aspiration of pulmonary embolism leading to diagnosis of hepatocellular carcinoma tumor embolus and change in systemic chemotherapy

Abstract

The management of metastatic hepatocellular carcinoma (HCC) is complex, particularly when complicated by pulmonary embolism. In these cases, atezolizumab-bevacizumab therapy is contraindicated due to an elevated risk of thromboembolic events. Differentiating pulmonary tumor embolism from thromboembolic disease is diagnostically challenging. This report outlines the benefit of transcatheter aspiration to obtain pathological evidence of pulmonary artery tumor embolus in an HCC patient. The intervention enabled a significant shift in the management strategy, leading to an escalation of systemic HCC therapy. This case underscores the importance of precise diagnostic techniques such as transcatheter aspiration in guiding treatment decisions, particularly in cases where pulmonary embolism may signify an underlying malignancy-driven process.

Keywords: INARI; Pulmonary embolism; hepatocellular carcinoma; tumor thrombus.

Figure 1.

Mechanical aspiration of the left pulmonary artery (a), (b) Computed tomography angiography revealed pulmonary artery emboli in the left main pulmonary artery (*) and pulmonary metastasis (#). The smaller thrombus in the right segmental upper lobe artery is not shown. (c) Digital subtraction angiogram (DSA) before the intervention with a clear visualization of the embolus in the left main pulmonary artery (*). (d) DSA of the pulmonary arteries shows the near-complete embolus removal with only wall-adherent residual embolus remaining without any flow impairment.

Figure 2.

Extracted pulmonary emboli Anatomical sketch of the pulmonary arteries showing an extensive HCC tumor embolus extracted from the left main pulmonary artery and a small thrombus from the right segmental upper lobe artery.

Figure 3.

Histopathologic examination Microscopic examination of a specimen extracted from the pulmonary artery revealed cellular clusters of an epithelioid tumor with focal necrosis intermingled with adherent microthrombi. The neoplastic population consisted of polygonal cells with enlarged round nuclei and abundant eosinophilic cytoplasm with signs of vacuolation. The chromatin texture was slightly condensed, forming occasionally prominent nucleoli. (a) Lesion at scanning magnification (hematoxylin-eosin stain, x100); (b) Morphological features under power magnification (hematoxylin-eosin stain, x400).

Figure 4.

(a), (b) Follow-up Computed tomography angiography (3 months after chemotherapy change) revealed stable wall-adherent pulmonary artery emboli in the left main pulmonary artery with calcification (*) and regressive pulmonary metastasis (#).