Cardiac Wall Mass Identified by Endobronchial Ultrasonography

To the Editor: Role of convex-probe endobronchial ultrasound (CP-EBUS) has been well described in the literature for the evaluation and sampling of mediastinal and hilar lymph nodes. Recently, it has been known to detect incidental pulmonary vascular diseases such as central pulmonary embolism.1,2 As the use of CP-EBUS gains popularity, experienced operators will continue to find its new applications. We describe a case of non–small cell lung carcinoma (NSCLC) extending to the heart. We believe that the latter could not have been diagnosed if we were not using CP-EBUS. A 78-year-old African American woman with a long-standing smoking history presented with 3 weeks of chest pain, fever, and dyspnea. A computed tomography of the chest with intravenous contrast revealed multiple subsegmental pulmonary artery emboli, left hilar lymphadenopathy, and a 5×4-cm-thick–walled cavity in the left lower lobe (LLL) (Fig. 1). The patient underwent a diagnostic flexible bronchoscopy and a CP-EBUS-guided transbronchial needle aspiration of lymph node stations 4R, 7, and 11L, as well as transbronchial lung biopsies of the LLL mass. CP-EBUS of the pulmonary vascular structures and cardiac images showed a mass projecting from the left atrial wall (Fig. 2, Supplementary Video, Supplemental Digital Content 1, https://links.lww.com/LBR/A98). Consequently, the abnormality was confirmed by an intraprocedural transesophageal echocardiogram performed by a cardiologist. In our case, CP-EBUS revealed an unsuspected extension of the primary tumor to the cardiac chambers and was able to correctly stage the disease. Biopsy results revealed squamous cell carcinoma in the LLL and station 7 samples.FIGURE 1: Computed tomography (mediastinal windows) contrast-enhanced image revealing partial filling of the pulmonary veins and left atrium by presumed tumor and thrombus.FIGURE 2: Convex-probe endobronchial ultrasound image demonstrating echogenic sessile mass (arrow) arising from the wall of the left atrium.The incidence of cardiac malignancy is rare but not negligible. The rate of metastatic disease to the myocardium and the pericardium is 20 times more common than the primary tumors.3 Tumor may involve the pericardium or the heart by 4 mechanisms: hematogenous spread, contiguous extension, transvenous extension, or retrograde lymphatic extension.4 Direct extension of tumors into the heart may occur in patients with bronchogenic tumors, esophageal carcinoma, breast carcinoma, or mediastinal lymphoma.5 Direct extension of NSCLC into the heart, pericardium, or great vessels represents T4 tumor grade. Under the seventh TNM classification, our patient would have been considered a T2bN2M0 (IIIA), whereas CP-EBUS was able to correctly stage this patient as T4N2M0 (IIIB).6 Even if the patient had been evaluated further by using positron emission tomography, this detection would have been missed because of the hypermetabolic activity of the cardiac tissue. It is important to remember that mediastinal invasion that may be technically resectable includes limited invasion to the pericardium, phrenic nerve, pleura, or fat. However, tumors involving invasion to the heart, great vessels, trachea, esophagus, vertebral bodies, or tracheal carina are considered T4 and carry an overall 5-year survival of <10%. Few reports describe surgical treatment of tumors, involving the left atrium, as seen on our patient. Fukuse et al7 describe 42 patients with NSCLC invading great vessels and left atrium. Those patients with left atrial involvement had a mean survival time of 10 months and 0% 3-year survival. This is significantly worse than those with SVC or aortic involvement. As previously described by MacEachern et al8 and exemplified in our case, CP-EBUS is a very accurate diagnostic tool, capable of identifying and confirming vascular and cardiac tumor invasion.