Great vessels invasion by NSCLC in a patient suspected of pulmonary embolism

Issue: April 10, 2010

ByMunir Ghesani, MD, FACNM

ByLiana Makarian, MD

ByEsha Gupta, MD

A 67-year-old woman with an extensive history of smoking initially presented complaining of a persistent cough. An evaluation with chest CT showed a 6.7-cm left upper lobe cavitary lesion extending to the hilum with enlarged bilateral mediastinal adenopathy.

The endobronchial biopsy revealed a poorly differentiated squamous cell carcinoma consistent with a primary lung cancer. Her subsequent PET/CT showed additional findings in the right upper lobe with hypermetabolic activity, but without anatomic correlate, as well as a diffuse thickening of the left adrenal gland with an associated hypermetabolic activity. The findings were strongly suggestive of metastatic disease, but the definitive biopsy of the contralateral lung and the adrenal lesion were thought not to be feasible. As such, she was started on palliative systemic chemotherapy with carboplatin and paclitaxel.

She continued to have a cough, weight loss and a declining performance status. As suspected, the restaging CT scan showed the persistent cavitary neoplasm with increased bronchial component and complete atelectasis of the left upper lobe. There was a concern for obstruction of the left lower lobe bronchus secondary to endobronchial component in the left distal mainstem bronchus. As such, she underwent an endobronchial stenting of the left distal main bronchus, with the successful subsequent aeration of the left lower lobe.

Figure 1: Axial CT angiogram images of the chest through the left pulmonary artery; tumor invasion of the left pulmonary artery.

She was treated with external beam radiation therapy in a palliative fashion to the left hilum at a dose of 30 Gy, and then started on erlotinib (Tarceva; OSI, Genentech). Unfortunately, three month later, the follow-up CT scan and the repeat flexible bronchoscopy again showed complete occlusion of the left upper bronchus and a new mucosal tumor present beyond the distal aspect of the left stent in the left distal mainstem bronchus. In order to control the aggressive disease, she was evaluated in consultation with the radiation oncology department and received endoluminal high-dose rate brachytherapy through an endobronchial catheter at a total dose of 22.5 Gy in three fractions.

She remained clinically relatively stable and continued on erlotinib for another three months until she was hospitalized with progressive severe chest pain and shortness of breath. Upon examination, she had reproducible chest wall tenderness and hypoxia. CT angiogram was requested for assessment of suspected pulmonary embolism. Instead, it showed invasion of the left pulmonary artery and left upper lobar artery branch with the tumor, without bland pulmonary thrombus. There was also a complete occlusion of the left superior pulmonary vein and direct extension of the tumor with the invasion of the anterior chest wall and ribs.

Figure 2: Axial CT angiogram images of the chest through the left pulmonary artery; Extension of the tumor from the left pulmonary artery to the bifurcation of the left upper lobar artery branch with narrowing of the artery.

Discussion

Lung cancer occurs in proximity to the large blood vessels. Gross vascular invasion was first described by Weller in 1929. He noted that the superior vena cava, pulmonary arteries and veins are frequently affected by the tumor. It was later found that the elastica offers no effective barrier to the malignant cells. The frequency of gross vascular invasion, based on the examination of surgical specimens reported in the literature, is about 30% to 40%. In the metastatic settings, tumor resection will likely result in a decreased survival.

Historically, NSCLC with T4 tumors involving great vessels were considered to be a relative contraindication to surgery. Limited invasion of the proximal pulmonary artery or vein, arterial wall or phrenic nerve does not necessarily contraindicate total surgical removal. However, once N1 or N2 disease is present, the chance of total cure is highly decreased. Wang and colleagues recently reviewed a cohort of 105 patients with tumors invading the left atrium, superior vena cava and intrapericardial pulmonary artery and found that for the N0 group the OS at five years was 41% compared with 11.8% for the N2 group.

Figure 3: Axial CT angiogram images of the chest through the main pulmonary artery; Tumor infiltration of the left upper lung along mediastinal and lateral pleural surfaces and invasion of the anterior left chest wall (arrow).

Photos courtesy of M. Ghesani, MD

Once the great vessels are affected, the resection is usually pneumonectomy. To spare the lung parenchyma, angioplastic procedures requiring removal of a portion of the arterial wall, or a circumferential resection with arterial reconstruction, have been used.

Surgical resection remains an important part of therapy for patients with locally advanced lung cancer. Modern techniques of chest wall resection and reconstruction, and bronchoplastic procedures, allow complete resection of locally advanced tumors with favorable five-year survival rates and low morbidity and mortality.

Liana Makarian, MD, is an Oncology Fellow at St Luke’s-Roosevelt Hospital Center.

Esha Gupta, MD, is Radiology Resident at St Luke’s-Roosevelt Hospital Center.

Munir Ghesani, MD, is an Attending Radiologist at St. Luke’s-Roosevelt Hospital Center and Associate Clinical Professor of Radiology at Columbia University College of Physicians and Surgeons.

For more information:

Costanzo A. Clin Cancer Res. 2005;1:5038s-5044s.

Galetta D. Lung Cancer. 2006;53:241-243.

Peyce D. J Pathol Bacteriol. 1960;79:141-146.

Wang X. CMJ. 2010;123:265-268.