[Contribution of ultrasonography in thyroid diseases. Apropos of 100 cases]

Thyroid disease is a very common disease, essentially affecting women, and raises diagnostic and therapeutic problems. The objective of this study was to specify the value of ultrasonography in the diagnosis and aetiological orientation of these lesions, based on a retrospective study of 100 patients. The results of ultrasonography were compared to the histological results. The aetiologies detected were dominated by benign lesions, particularly adenomas (56 cases), dystrophic goitres (32 cases) and cancers (7 cases). Ultrasonography allowed the detection of clinically impalpable nodules with no isotope scan signs in 11% of cases. The ultrasonographic appearance of benign nodules was variable. Solitary nodules were detected in 63 cases. They were hyperechoic in 15 cases, isoechoic in 8 cases, cystic in 9 cases, and mixed in 31 cases. A peripheral clear halo was revealed in 25 cases and macrocalcifications were present in 17 cases. Malignant lesions were visualized in 7 cases and were solitary in 5 cases. Solitary lesions had a hypoechoic echostructure in 1 case, an isoechoic echostructure in 2 cases and a mixed echostructure in 2 cases. The margins were poorly demarcated in 3 cases, and circumscribed without peripheral halo in 2 cases. Cervical lymphadenopathy was detected in 2 cases. Graves' disease, diagnosed in 2 patients, showed a diffuse hypoechoic appearance of the entire thyroid gland. Ultrasonography is a sensitive morphological method for the diagnosis of thyroid lesions. A detailed and precise analysis of the ultrasound signs of the lesion can suggest that benign or malignant nature of the lesion, which can be completed by Doppler-ultrasound and especially ultrasound-guided needle biopsies.