Clinical utility of bone scan features of pleural effusion: sensitivity and specificity for malignancy based on pleural fluid cytopathology.
Asymmetric chest activity with malignant and benign pleural effusions has been described in bone scans. However, the clinical utility of this finding is not elucible from the literature. We developed specific scintigraphic criteria for malignant pleural effusion and retrospectively assessed their sensitivity and specificity in a group of patient scans.


METHODS
Pleural fluid was submitted for cytopathology from 850 patients over a 5-yr period. Bone scans were done within 2 mo of the thoracentesis in 74 patients. As a consensus panel, we reread the scans and reviewed the cytology.


RESULTS
The effusions were cytologically malignant in 25/74 patients (34%), indeterminate in 9/74 (12%) and benign in 40/74 (54%). Based on cytopathology, malignant pleural effusions were detected by bone scans with a sensitivity of 34%-50% and a specificity of 78%-89%; true sensitivity and specificity was somewhere in between averaging 42% (95% confidence interval 24%-60%) and 84% (95% confidence interval 73%-95%), respectively.


CONCLUSIONS
The bone scan is frequently the first examination suggesting pleural metastasis, and when it is detected it should be pursued beyond pleural fluid cytology, if negative or indeterminate.
Sandler
E D
ED
Department of Radiology, University of California San Francisco 94143-0252.
Hattner
R S
RS
Parisi
M T
MT
Miller
T R
TR
D000328:Adult; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013669:Technetium Tc 99m Medronate
D013669:Technetium Tc 99m Medronate