Rib enlargement in patients with chronic pleural disease.

OBJECTIVE: The purpose of this study was to assess the width of ribs in patients with chronic pleural disease. MATERIALS AND METHODS: On posteroanterior radiographs, we measured the horizontal width of ribs in the midaxillary line of four groups of patients: 41 selected patients with widened ribs and chronic pleural disease (group I), 30 consecutive patients with the clinical diagnosis of tuberculosis for 5 or more years who had radiographs that showed unilateral pulmonary or pleural disease (group II), 25 consecutive patients with the clinical diagnosis of empyema who had radiographs that showed unilateral pleural and often pulmonary parenchymal disease (group III), and 60 consecutive persons who received routine preemployment examinations that revealed no pulmonary or pleural disease (control subjects). Available clinical data were reviewed. RESULTS: We found a significant difference between the size of the ribs on the side of disease and the nondiseased side for groups I and II (p = .0008 and p = .045, respectively). We found no such difference for group III or the control group. The mean absolute values of the different widths of ribs on the side of disease and the nondiseased side were greater for groups I, II, and III than the absolute values of the different widths for the right and left ribs of the control subjects (p < .05). We identified tuberculosis, nontubercular empyema, thoracic surgery, blunt trauma, and metastatic tumor as causative agents in 24 (59%) of the 41 patients in group I. CONCLUSION: Rib enlargement is occasionally displayed radiographically in cases of chronic pleural disease and is confirmed by comparison of the two sides. In our selected patients (group I) with rib enlargement, tuberculosis was the most common cause of pleural disease, but nontubercular empyema, thoracic surgery, blunt trauma, and metastatic tumor were also found. Conversely, we found no rib enlargement in association with pleural disease of short duration. We have shown that rib enlargement can indicate the chronicity of pleural disease.