Color Doppler sonography patterns related to histological findings in Graves' disease

The aim of this work was to correlate color duplex sonography (CDS) patterns and thyroid histology in hyperthyroid Graves' disease (GD) patients. Sixteen patients with relapsed GD were studied. Before starting a new cycle of medical therapy with methimazole in decreasing doses for 3 to 6 months (baseline study), the patients underwent functional, autoimmune, and CDS studies. The same studies were carried out again just before surgery (presurgical study) after medical therapy had produced a normalization of thyroid hormone serum levels. The thyroid glands were histologically examined and their patterns were compared with CDS patterns. Thirty-three normal subjects were used as a control group. At baseline, 6 patients (group I) had intraparenchymal homogeneous vascular color spots or diffusely distributed over the parenchyma lobe or in areas alternating with avascular zones (CDS-A pattern). In 8 patients (group II) the thyroid had vascular bands with avascular or poorly vascularized parenchymal areas (CDS-B pattern). In 2 patients, the 2 patterns were present in the same thyroid (A-B pattern or mixed pattern). In these 2 patients the histological aspects were more similar to the CDS-B pattern than the CDS-A pattern. The 2 groups of patients differed in the velocity of systolic peak (VP) that was significantly higher in group I than in group II. In the presurgical study, no changes relative to CDS patterns were observed in patient groups I and II. The VP did not show any appreciable modifications in either group of patients. The thyrotropin-stimulating antibodies (TRAb) returned to normal levels in group II, but not in group I. The 2 CDS patterns, observed in the baseline study, were histologically characterized either by a richly vascularized parenchyma with prevalent endothelial hyperplasia (parenchymatous goiter, CDS-A) or by fibrotic septation with prevalent vascular intimal hyperplasia (CDS-B). In conclusion, this CDS study in GD patients showed 2 distinct vascular patterns. The thyroid glands were histologically characterized by either a richly capillary vascularized parenchyma (parenchymatous goiter, CDS-A aspect) or by fibrotic septation with prevalent intraseptal arteriolar-like hyperplasia (fibrous goiter, CDS-B aspect). Such differences may be secondary to a different duration of hyperthyroidism and/or intensity of TRAb thyroid stimulation.