Sonographic evaluation of unexplained pleural exudate: a prospective case series.
BACKGROUND
Thoracic ultrasound may be helpful in differentiating between malignant and tuberculosis-associated pleural exudate. This study aimed to evaluate its utility in patients with unexplained pleural exudate.


METHODS
Consecutive patients were screened and pleural effusion was found in 278 patients. Pleural exudate was present in 106 patients and remained undiagnosed after biochemical and cytological evaluation in 40 patients (median age 58 years, 67% men) who then underwent detailed thoracic ultrasound for the presence of complex (septated or fibrous) or anechoic patterns. Pleural needle biopsy or thoracoscopy with histological evaluation were used for definitive diagnosis.


RESULTS
History, clinical characteristics and routine procedures including cytology were not helpful in differential diagnosis. Pleural specimens for histological evaluation were obtained from all 40 patients and confirmed tuberculosis in 12 patients, cancer in nine and nonspecific pleuritis in 19. Sonographic finding of a complex septal pattern was present only in patients with tuberculosis (positive predictive value 100%); anechoic appearance was suggestive of nonspecific pleuritis (positive predictive value 65%).


CONCLUSIONS
Thoracic ultrasound is a useful bedside method for differentiation of the etiology of pleural exudate. When a complex septal pattern is found, pleural needle biopsy should be the next diagnostic procedure, whereas with less complex pleural sonography findings other methods should be pursued.
Marcun
Robert
R
University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia. robert.marcun@klinika-golnik.si
Sustic
Alan
A
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D007958:Leukocyte Count; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010994:Pleura / Q000000981:diagnostic imaging / Q000473:pathology; D010995:Pleural Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D010996:Pleural Effusion / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D016066:Pleural Effusion, Malignant / Q000000981:diagnostic imaging; D010997:Pleural Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D010998:Pleurisy / Q000000981:diagnostic imaging / Q000473:pathology; D019095:Point-of-Care Systems; D011446:Prospective Studies; D017524:Slovenia; D013906:Thoracoscopy; D014396:Tuberculosis, Pleural / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography
D015415:Biomarkers; D007770:L-Lactate Dehydrogenase