Peak expiratory flow in the detection of retrosternal goitre.

In 24 patients where the lower border of a cervical goitre was poorly defined, the value of simple lung function tests in the prediction of the presence of a retrosternal goitre was assessed. At operation there were nine patients with retrosternal extension (Group I) and 15 without (Group II). The preoperative PEF ratio (observed to predicted) was significantly different between the two groups (P = 0.004) with a positive predictive value of 90% for a retrosternal goitre. This difference was abolished after thyroidectomy. There was a significant improvement in PEF in patients with retrosternal goitres after thyroidectomy (P less than 0.001). It is concluded that the preoperative measurement of PEF is a simple method of detecting the retrosternal extension of a cervical goitre.