title: Endoscopic ultrasound-guided fine-needle aspiration biopsy for lymphadenopathy of unknown origin.
abstract: OBJECTIVE
  The diagnosis of mediastinal and intra-abdominal lymphadenopathy is sometimes difficult, especially in patients who have no other primary lesions. Lymphoma is one of the main causes of this condition. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a safe and accurate diagnostic procedure for lesions surrounding the gastrointestinal tract. However, diagnosing lymphoma using the EUS-FNA technique remains a diagnostic challenge, due to limitations in the amount of material sampled. The aim of the present study was to evaluate the yield of EUS-FNA biopsy (EUS-FNAB) using a large-gauge needle in patients with mediastinal and intra-abdominal lymphadenopathy of unknown origin, especially in relation to subclassification of the lymphomas.
  
  
  METHODS
  Consecutive patients with mediastinal and intra-abdominal lymphadenopathy of unknown origin who were referred between October 2003 and March 2005 were enrolled in the study. EUS-FNAB was carried out using a 19-gauge needle, passing through the esophageal, gastric, and duodenal walls. Pathological diagnoses were made on the basis of histological findings, including immunopathological staining.
  
  
  RESULTS
  A total of 104 patients were included in the study. The locations of the lymph nodes were mediastinal in 50 patients, intra-abdominal in 48 patients, and both mediastinal and intra-abdominal in six patients. The diagnoses made using EUS-FNAB were lymphoma (n = 48), metastasis (n = 16), and benign/reactive (n = 40). The overall accuracy of EUS-FNAB for unknown lymphadenopathy was 98 %, and it was possible to classify the lymphomas in accordance with the World Health Organization classifications in 88 % of cases. No serious complications occurred with the procedure.
  
  
  CONCLUSIONS
  Open thoracic surgery, laparotomy, and other invasive diagnostic procedures such as mediastinoscopy and laparoscopy can now be avoided, as EUS-FNAB is potentially a safe and accurate tool for diagnosing unknown lymphadenopathy, including lymphoma.
authors.affiliation: First Department of Internal Medicine, Gifu University, Gifu, Japan. yasudaic@aol.com
authors.forename: I
authors.initials: I
authors.lastname: Yasuda
authors.forename: H
authors.initials: H
authors.lastname: Tsurumi
authors.forename: S
authors.initials: S
authors.lastname: Omar
authors.forename: T
authors.initials: T
authors.lastname: Iwashita
authors.forename: Y
authors.initials: Y
authors.lastname: Kojima
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: M
authors.initials: M
authors.lastname: Sawada
authors.forename: T
authors.initials: T
authors.lastname: Takami
authors.forename: H
authors.initials: H
authors.lastname: Moriwaki
authors.forename: N
authors.initials: N
authors.lastname: Soehendra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle / Q000379:methods*; D019160:Endosonography; D005260:Female; D006801:Humans; D008206:Lymphatic Diseases / Q000175:diagnosis* / Q000209:etiology; D008223:Lymphoma / Q000175:diagnosis*; D016393:Lymphoma, B-Cell / Q000175:diagnosis; D016399:Lymphoma, T-Cell / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity