title: Intrathoracic lymphadenopathy in patients with empyema.
abstract: OBJECTIVE
  Our goal was to determine the prevalence of intrathoracic lymphadenopathy on chest CT in patients with empyema.
  
  
  METHODS
  We retrospectively identified 27 patients (14 men, 13 women, mean age 43 years) with nontuberculous empyema examined with chest CT. All scans were reviewed by two of three board-certified radiologists for the presence of intrathoracic lymphadenopathy (> or = 1 cm, short axis) in an American Thoracic Society (ATS) nodal station or the internal mammary region. Differences were resolved by consensus.
  
  
  RESULTS
  Thirteen (48%) patients with empyema had lymphadenopathy on chest CT. The mean number of enlarged lymph nodes for the patients with lymphadenopathy was 3.2 (SD +/-2.3, range 1-8). The mean size of the largest lymph node was 1.4 cm (range 1.0-2.5 cm). The lymphadenopathy was unilateral and ipsilateral to the empyema in seven (54%), bilateral in five (38%), and unilateral contralateral to the empyema in one. The distribution of lymphadenopathy according to ATS nodal stations was 4R (n = 8), 7 (n = 6), 10R (n = 5); n = 2 each 2R, 10L, 11L; and n = 1 each 11R, 2L, 4L, and 6. Four patients had internal mammary lymphadenopathy. Pleural fluid and smooth pleural thickening were present in each case. Four patients had follow-up CT after treatment. There was a decrease or resolution of the lymphadenopathy in each case.
  
  
  CONCLUSIONS
  Intrathoracic lymphadenopathy is a common CT finding in patients with empyema and occurred in 48% of this series. In patients with smooth pleural thickening and pleural effusion, intrathoracic lymphadenopathy should not be used as a criterion to differentiate empyema from malignant or tuberculous pleural effusion.
authors.affiliation: Department of Radiology, Albert Einstein College of Medicine, Jacobi Medical Center, Bronx, NY 10461, USA.
authors.forename: L B
authors.initials: LB
authors.lastname: Haramati
authors.forename: D D
authors.initials: DD
authors.lastname: Alterman
authors.forename: C S
authors.initials: CS
authors.lastname: White
authors.forename: A S
authors.initials: AS
authors.lastname: Kerr
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004653:Empyema / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D013896:Thoracic Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology; D014057:Tomography, X-Ray Computed