Pleural effusion: undiagnosed: thoracoscopy was a useful investigation for diagnosing malignancy.

Clinical bottom line (level 4)

  1. In patients with undiagnosed pleural effusion, malignancy was common.
  2. A positive thoracoscopy made malignancy very likely, whilst a negative one made it unlikely.
Menzies and Charbonneau: Annals of Internal Medicine 1991; 114 (4): 271-276
Expires October 2003

The study

Setting: university hospital, Canada

102 patients (aged mean 63 years, 69% male) undiagnosed pleural effusions following routine evaluation (including at least one thoracentesis and needle biopsy)

Excluded if
  • considered unable to tolerate a 20 to 30% pneumothorax
  • confused or unable to co-operate
  • pCO2 > 50 mmHg



    • Independent unblinded reference standard, applied in all patients from a consecutive appropriate spectrum.
    Reference standard:
      • thoracotomy, autopsy
      • another definite diagnosis made (e.g. pulmonary embolism)
      • pleural disease and signs and symptoms resolved or remained stable on follow-up for one year (95% followed up)
    Diagnostic test: thoracoscopy under local anaesthetic with mild sedation with visually-directed biopsies

    The evidence

    pre-test probability of malignancy: 42%, (95% CI: 32% to 52%)

    diagnostic test malignancy no malignancy LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    positive thoracoscopy 38 5 11
    (4.5 to 24)     		88% 0.10
    (0.041 to 0.27)     		7%
    total 42 58

    • These results assume that all patients lost to follow-up had malignancy.
    • There were two major complications- one ventricular tachycardia with collapse; one massive subcutaneous emphysema.
    • There were eight minor complications- air leak, fever and excessive bleeding.

    Citation

    1. Menzies R, and Charbonneau M: thoracoscopy for the diagnosis of pleural disease. Annals of Internal Medicine 1991; 114 (4): 271-276
    Search Terms: reference from Pleural effusion chapter in 'Quick Consult Manual to Evidence-based Medicine': publd Lippincott-Raven, 1997
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient undiagnosed pleural effusion
    Intervention or Exposure thoracoscopy
    Outcome diagnosis of malignancy