Asbestos-related pleural diseases: dimensional criteria are not appropriate to differentiate diffuse pleural thickening from pleural plaques.
BACKGROUND
In the literature, the criteria used to define pleural plaques (PP) and diffuse pleural thickening (DPT) are very heterogeneous and often imprecise. A multicenter restropective study was conducted to assess the relevance of two radiographic definitions of DPT.


METHODS
The study population consisted of 287 subjects with asbestos-related pleural thickening. Two definitions were used to characterize DPT on postero-anterior chest radiographs: definition 1: pleural thickening associated with obliteration of the costophrenic angle; definition 2: pleural thickening at least 5 mm wide, extending for more than one quarter of the chest wall. Prevalence of respiratory symptoms and pulmonary function tests were compared in the DPT and PP groups resulting from the two definitions of DPT.


RESULTS
According to definition 1, 34 patients (11.8%) were classified in the DPT group. Prevalence of chronic sputum, dyspnea, and chest pain was significantly higher in this group than in the PP group. FEV(1), FVC, and TLC were significantly lower. The differences persisted after adjustment for confounding factors. According to definition 2,102 patients (36.6%) were classified in the DPT group. DPT and PP groups did not differ in terms of prevalence of respiratory symptoms, or pulmonary function tests. Agreement between readers was significantly better when using definition 1.


CONCLUSIONS
Obliteration of costophrenic angle is a much more reliable sign than dimensional criteria to characterize DPT.
Unité de Pathologie Professionnelle et de Santé au Travail, Hôpital Raymond Poincaré AP-HP, Garches, France. jacques.ameille@rpc.ap-hop-paris.fr
Jacques
J
Ameille
Mireille
M
Matrat
Christophe
C
Paris
Nathalie
N
Joly
Claude
C
Raffaelli
Patrick
P
Brochard
Yuriko
Y
Iwatsubo
Jean Claude
JC
Pairon
Marc
M
Letourneux
D001194:Asbestos / Q000633:toxicity*; D001195:Asbestosis / Q000145:classification* / Q000000981:diagnostic imaging*; D002637:Chest Pain / Q000209:etiology; D004417:Dyspnea / Q000209:etiology; D005260:Female; D005602:France; D006801:Humans; D008297:Male; D008875:Middle Aged; D010995:Pleural Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D013183:Sputum / Q000378:metabolism; D014057:Tomography, X-Ray Computed
D001194:Asbestos