title: Combined use of EUS-guided FNA and immunocytochemical stains discloses metastatic and unusual diseases in the evaluation of mediastinal lymphadenopathy of unknown etiology.
abstract: OBJECTIVE
  Mediastinal lymphadenopathy (ML) is a cause for concern, especially in patients with previous malignancy. We report our experience with the use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with immunocytochemical stains in patients being evaluated for ML.
  
  
  METHODS
  Retrospective analysis of patients with ML of unknown origin who underwent EUS-FNA. On-site evaluation was performed by experienced cytologist, and special immunocytochemical stains were requested as indicated.
  
  
  RESULTS
  A total of 116 patients were included, and a total of 136 mediastinal LN were sampled. Prior malignancy was present in 45%. The most common site of examined lymph node (LN) were subcarinal (76%, 103 LN). The median long and short axis diameters were 28 mm and 13 mm, respectively. FNA was read on-site as malignant, 21 (16%); benign, 100 (76.9%); suspicious, six (4%); atypical, 3 (2%); and inadequate sample, six (4%). Sixty-four LN were deferred for additional studies; 22 for immunocytochemical and 26 for Gimesa (GMS) stain and 21 for flow cytometry. Final FNA read was malignant in 28 (21%), benign in 103 (76%), suspicious in three (2%), and atypical in two (1%). Metastatic malignancies disclosed included Hodgkin's and Non-Hodgkin's lymphoma, melanoma, hepatoma, breast, lung, colon, renal, endometrial, Fallopian tube, and unknown carcinoma. The sensitivity, specificity, and accuracy of the final FNA read to predict malignancy were 100%.
  
  
  CONCLUSIONS
  EUS-guided FNA with additional ancillary studies is useful in disclosing metastatic ML from a variety of neoplasms. Due to its safety and accuracy profile, it should be considered the test of choice in evaluating abnormal ML in appropriately selected patients.
authors.affiliation: Division of Gastroenterology and Hepatology, The University of Alabama at Birmingham, Birmingham, Alabama, Lebanon.
authors.forename: Mohamad A
authors.initials: MA
authors.lastname: Eloubeidi
authors.forename: Ali S
authors.initials: AS
authors.lastname: Khan
authors.forename: Leticia P
authors.initials: LP
authors.lastname: Luz
authors.forename: Ami
authors.initials: A
authors.lastname: Linder
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Moreira
authors.forename: David R
authors.initials: DR
authors.lastname: Crowe
authors.forename: Isam A
authors.initials: IA
authors.lastname: Eltoum