Pleural effusion: normal pleural biopsy or fluid cytology did not rule out malignancy.

Clinical bottom line (level 4)

  1. Malignancy was a common cause of pleural effusions.
  2. A positive pleural fluid cytology result or positive needle biopsy was diagnostic of malignancy.
  3. Neither test if negative could safely exclude malignancy.
  4. 7% of patients with normal cytology had malignancy on biopsy.
Prakash and Reiman: Mayo Clinical Protocols 1985; 60: 158-164
Expires October 2003

The study

Setting: university hospital, USA, 1973 to 1982

414 patients (aged range 18 to 87 years; mean 60, 58% male) with pleural effusions who had thoracentesis and needle biopsy

?independent unblinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
Reference standard:
  • other biopsies, clinical features, operation or autopsy
Diagnostic test:
  • needle biopsy (using a Cope or Abrams needle)
  • cytology of pleural fluid

The evidence

pre-test probability of malignancy: 68%, (95% CI: 63% to 72%)

diagnostic test malignancy no malignancy LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
positive needle biopsy 163 0 inf
(26 to inf) 		100% 0.42
(0.37 to 0.48) 		47%
positive cytology of pleural fluid 135 0 inf
(22 to inf) 		100% 0.52
(0.46 to 0.58) 		52%
total 281 133

  • In 7.1% of patients with negative cytology, biopsy demonstrated a malignant effusion.

Citation

  1. Prakash UB, and Reiman HM: comparison of needle biopsy with cytologic analysis for the evaluation of pleural effusion: analysis of 414 cases. Mayo Clinical Protocols 1985; 60: 158-164
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 pleural effusion
Intervention or Exposure pleural fluid cytology or needle biopsy
Outcome malignancy