Salvage lobectomy for an intravascular mass occluding the right lower lobe vein

Tumor in the pulmonary vein.

Central Message.

An intravascular mass of pulmonary vessels presents a diagnostic and therapeutic challenge.

An intravascular mass of pulmonary vessels presents a diagnostic and therapeutic challenge. The diagnoses include thrombosis, embolism, and a tumor, which is typically primary sarcoma.¹ Among secondary tumors of pulmonary vessels, a metastasis from an extrathoracic malignancy is extremely rare and that from gastric carcinoma has not been reported, as far as we are aware. Management of an intravascular mass depends on the clinical diagnosis and presentation, given the difficulty of histological diagnosis by biopsy. Here, we describe the diagnostic and therapeutic challenges of an intravascular mass in the right lower lobe pulmonary vein complicated by multiple brain nodules in a patient with a history of gastric carcinoma. The institutional review board of Nara Medical University approved the study (No. 3860, August 21, 2024). The patient provided informed written consent for publication of this report.

Case Presentation

A 74-year-old man with worsening dyspnea was referred to our hospital. He had been diagnosed with pulmonary vein thrombosis by contrast-enhanced computed tomography 3 months earlier (Figure 1, A) and had since received anticoagulant therapy. He had a history of laparoscopic-assisted distal gastrectomy and Billroth I reconstruction, followed by adjuvant chemotherapy for T1b N1 M0 gastric carcinoma 3 years before presentation. Subsequently, weakness and numbness developed in the right lower extremity, and cerebral infarction was suspected. Head magnetic resonance imaging showed 8 brain metastases. A systemic evaluation was conducted due to suspicion of an event related to malignant cancer. Fluorodeoxyglucose-18 (FDG) positron emission tomography revealed a mass with strong FDG uptake in the right lower pulmonary vein (Figure 1, B), leading to diagnosis of malignant embolism. Dyspnea was believed to be associated with progressive pulmonary edema secondary to complete occlusion of the right lower vein. The preoperative diagnosis was pulmonary vein angiosarcoma with oligo-metastases to the brain.

Figure 1.

A, Computed tomography 3 months before referral. B, Positron emission tomography of an embolus in the right lower pulmonary vein. C, Computed tomography before surgery.

Because complete tumor resection and radical stereotactic radiotherapy for presumed brain metastases were feasible, salvage surgery was performed. This included en bloc right lower lobectomy with en bloc pulmonary vein/left atrial resection, with use of cardiopulmonary bypass. Division of the right lower lobe pulmonary artery and bronchus via median sternotomy would have been extremely challenging; therefore, thoracoscopic surgery in a lateral position was selected. Preoperative computed tomography (Figure 1, C) showed the tumor extending into the left atrium, which suggested that instead of using a surgical stapler, left atriotomy via median sternotomy would ensure macroscopic complete resection. Therefore, we started hilar dissection thoracoscopically in a lateral decubitus position (Figure E1), dividing the pulmonary artery and bronchus and dissecting the lower lobe vein, and then resected the lower lobe vein and the tumor in the left atrium en bloc via median sternotomy in a supine position, completing right lower lobectomy. Subsequently, the left atrial wall defect was reconstructed using a bovine pericardial patch (Video 1). The postoperative course was uneventful.

Figure E1.

Schema of port placement for thoracoscopic surgery.

Discussion

Preoperatively, the growing mass in the right lower pulmonary vein was believed to be primary angiosarcoma, but was found to be a metastasis from gastric carcinoma on final pathology, which has not been reported previously. It was challenging to obtain an accurate diagnosis preoperatively, but such a diagnosis would have allowed us to switch to chemotherapy or immunotherapy for gastric carcinoma. Aside from the diagnostic challenge, growth of the tumor into the left atrium was considered to be an indication for salvage surgery, given that the growing mass would result in lethal hemoptysis, right heart failure, and multiple systemic embolisms. It should be emphasized that resection of primary angiosarcoma combined with radiotherapy for brain metastases in this patient is controversial, whereas definitive local therapy with or without systemic therapy is an option for oligometastatic sarcoma or carcinoma.^2,3 The alternative approach is 2 thoracotomies (median sternotomy and right lateral thoracotomy) or right hemiclamshell incision,^4,5 but our approach may have resulted in the excellent postoperative recovery and prompt initiation of postoperative chemotherapy. The patient requires careful follow-up in the long term.

Conclusions

A tumor combined with the pulmonary vein and left atrium was resected successfully under cardiopulmonary bypass.

Conflict of Interest Statement

The authors reported no conflicts of interest.

The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.

Supplementary Data

Video 1

Intraoperative findings. Video available at: https://www.jtcvs.org/article/S2666-2507(24)00436-X/fulltext.