Journal of Thoracic Oncology:
Letters to the Editor
Dooms, Christophe MD, PhD; Vansteenkiste, Johan MD, PhD; Renterghem, Dirk Van MD; Leyn, Paul De MD, PhD
Department of Pulmonology, University Hospitals Leuven, Leuven, Belgium (Dooms, Vansteenkiste)
Department of Pulmonology, AZ Sint Jan Brugge, Belgium (Renterghem)
Department of Thoracic Surgery, University Hospitals Leuven, Leuven, Belgium, Leuven Lung Cancer Group, University Hospitals Leuven, Leuven, Belgium (De Leyn)
Disclosure: The authors declare no conflicts of interest.
Address for correspondence: Christophe Dooms, MD, PhD, Department of Pulmonology, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. E-mail: firstname.lastname@example.org
To the Editor:
Accurate mediastinal lymph node staging is pivotal in the staging and treatment of non-small cell lung cancer.1,2 Echoendoscopic needle aspiration is a minimally invasive staging technique with a good sensitivity and 100% specificity. However, physicians performing and relying on esophageal ultrasound-controlled fine needle aspiration (EUS-FNA) should be aware of potential hurdles related to this technique such as
Parenchymal lung lesions adjacent to the esophagus can be sampled and care must be taken in their radiographic and cytologic interpretation.
Lymphocytes in an needle aspiration sample do not always indicate a lymph node was sampled.
EUS-FNA may allow sampling of hilar lymph nodes.
As such, EUS-FNA may result in clinical overstaging (N2 instead of N0 or N1) having an important impact on patient treatment and prognosis. Here, we present two cases illustrating potential hurdles performing EUS-FNA for mediastinal staging.
A woman presented with a suspicious lung mass in the posterior part of the right lower lobe and a second mass adjacent to the esophagus that was considered a second parenchymal mass (sharp angles of the opacity) or a paraesophageal mediastinal lymph node (sharp angles because of lymph node volume) (Figure 1). EUS showed a round, well-defined hypoechogenic paraesophageal lesion revealing on needle aspiration cytology malignant cells embedded in lymphocytes. Therefore, the clinical stage was considered cT2N2M0. A cervical mediastinoscopy with nodal mapping showed normal lymph nodes (positions 2/4R, 4L, 7). At thoracotomy, we found a tumor in the right lower lobe and a second subpleural intraparenchymal ovoid tumor in the same lobe situated adjacent to the pleura at the level of the esophagus. Thus, pathologic characteristics of the resection specimen after right lower lobe lobectomy with systemic nodal dissection described two locations of solid pulmonary adenocarcinoma, staged as pT4N0, harboring lymphoid aggregates.3 Apparently, EUS-FNA and its cytologic interpretation suggested a mediastinal lymph node for a lesion, finally proven to be a parenchymal tumor.
Years ago, a man underwent chemoradiotherapy for Hodgkin’s disease; lung fibrosis due to bleomycin had occurred. Now, he presented with non-small cell lung cancer of the left lower lobe and Fluoro Deoxy Glucose Position Emission Tomography positive lymph nodes in the left hilum (level 11L) and in the paraesophageal level 8 (level 8L on CT; Fig. 2). EUS-FNA of the paraesophageal lymph node revealed malignant cells embedded in lymphocytes. The final clinical stage was considered cT2N2M0. Because of his medical history, he was not able to undergo chemoradiotherapy; we considered him operable after a negative cervical mediastinoscopy. During thoracotomy, we found a tumor in the left lower lobe with a malignant hilar lymph node at the ostium of the left lower lobe bronchus (level 10L). The final pathologic findings of the resection spec-imen was staged as pT2N1. Apparently, EUS-FNA had identified a lymph node as mediastinal, although it was finally proved to be a hilar lymph node.
In conclusion, caution must always be taken in the interpretation of the anatomy on imaging.4 Not only the implementation of the International Association for the Study of Lung Cancer lymph node map on computed tomography but also correct echoendoscopy interpretation is warranted to improve the N stage classification.
Christophe Dooms, MD, PhD
Johan Vansteenkiste, MD, PhD
Department of Pulmonology, University Hospitals Leuven
Dirk Van Renterghem, MD
Department of Pulmonology, AZ Sint Jan Brugge, Belgium
Paul De Leyn, MD, PhD
Department of Thoracic Surgery, University Hospitals Leuven
Leuven Lung Cancer Group, University Hospitals Leuven
1. Detterbeck FC, Jantz MA, Wallace M, Vansteenkiste J, Silvestri GA, American College of Chest Physicians. Invasive mediastinal staging of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition). Chest
2. De Leyn P, Lardinois D, Van Schil P, et al. ESTS guidelines for preoperative lymph node staging for non-small cell lung cancer. Eur J Cardiothorac Surg
3. Coppola D, Mulé J. Ectopic lymph nodes within human solid tumors. J Clin Oncol
4. Rusch V, Asamura H, Watanabe H, et al. The IASLC Lung Cancer Staging Project. A proposal for a new international lymph node map in the forthcoming seventh edition of the TNM classification for lung cancer. J Thorac Oncol 2009;4:568–577.