Symptoms Of Lymph Node Cancer
Metastatic Lung Cancer Without Regional Lymph Node Swelling - Letter to the EditorHiroaki Satoh To the Editor:
In order to better understand the etiology of distant metastasis with no regional lymph node swelling, a review of 891 patients with lung cancer who were admitted to our hospital from 1983 to 2000 has been undertaken. TNM staging[1] was performed by chest CT, abdominal CT, head CT, or brain MRI scans, and bone scintigraphy. Clinical stage NO was defined when neither mediastinal nor hilar lymph node measured [is greater than] 1.0 cm in diameter as detected on enhanced chest CT scan.[2] Thirty-one patients (3.5%) had distant metastasis with no regional lymph node swelling at the time of diagnosis. Histology included 26 adenocarcinomas (83.9%), 2 squamous cell carcinomas, 2 large cell carcinomas, and 1 small cell carcinoma. Twenty-three patients had good performance status (performance status of 0 to 1). The size of the primary lesion was not necessarily large (30 mm; nine patients). In 21 patients, metastases were confined in only one organ. The most common organs were lung, bone, and brain. Silent metastasis detected only by the imaging procedures was found in 21 patients. All these metastases detected by imaging procedures were confirmed as true-positive by following their clinical coarses.
CT scan has been important and useful for evaluation of hilar and mediastinal lymph nodes in lung cancer patients. However, the reliability of diagnostic criteria for node metastasis by node size on CT scan remains controversial.[3] It has been known that nonmalignant nodes may be enlarged because of reactive hyperplasia or obstructive pneumonia in squamous cell carcinoma.[4] On the other hand, metastatic nodes may appear normal in size if the metastasis is microscopic, especially in adenocarcinoma.[5] Our results suggest that a certain type of lung adenocarcinoma develops distant metastasis with no regional lymph node swelling, and such hematogenous distant metastasis may not necessarily associated with size of primary lesion. Although a small percentage of NO patients had distant metastasis, two thirds of them were silent. Considering the appropriate treatment for these patients, for patients with lung adenocarcinoma we do recommend full staging procedures using imaging studies even if they do not show any symptoms.
Hiroaki Satoh, MD
Hiroichi Ishikawa, MD
Yuko T. Yamashita, MD
Morio Ohtsuka, MD
Kiyohisa Sekizawa, MD
Institute of Clinical Medicine, University of Tsukuba
Tsukuba, Japan
Correspondence to: Hiroaki Satoh, MD, Division of Respiratory Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba-city, Ibaraki, 305-8575, Japan; e-mail: hirosato@md. tsukuba.ac.jp
REFERENCES
[1] Mountain CF. Revisions in the International System for Staging Lung Cancer. Chest 1997; 111:1710-1717
[2] Arita T, Kuramitsu T, Kawamura M, et al. Bronchogenic carcinoma: incidence of metastases to normal sized lymph nodes. Thorax 1995; 50:1267-1269
[3] McKenna RJ, Libshitz HI, Mountain CE, et al. Roentgenographic evaluation of mediastinal nodes for preoperative assessment in lung cancer. Chest 1985; 88:206-210
[4] Daly BD, Faling LJ, Pugatch RD, et al. Computed tomography: an effective technique for mediastinal staging in lung cancer. Thorac Cardiovasc Surg 1984; 88:486-494
[5] Gross BH, Glazer GM, Orringer MB, et al. Bronchogenic carcinoma metastatic to normal-sized lymph nodes: frequency and significance. Radiology 1988; 166:71-74
COPYRIGHT 2001 American College of Chest Physicians
COPYRIGHT 2001 Gale Group
|