Predictive value of sonographic features in preoperative evaluation of medullary thyroid carcinoma

Abstract

To summarize ultrasound features associated with medullary thyroid carcinoma (MTC) and investigate the predictive value of ultrasonography in preoperative diagnosis of MTC. The sonographic and clinical data were studied in a series of nodules histologically proven as MTC collected from January 1993 to January 2013. A total of 86 patients (92 nodules proven as MTC) were enrolled in the study with an average age of (47±12) years.Among the MTCs, 21.7%(20/92) were excluded because of missing data and the remained 78.3%(72/92) had complete data with the average diameter of (2.1±1.3) cm.The common US findings for MTC were solid, hypoechogenicity, regular sharp, well-defined margin, AP/ TR<1 and calcification (mostly microcalcification). Calcification and vascularization were more common in MTC nodules(48.6% vs 5.6%, P=0.001). Nodules with enlargement of cervical lymph node tended to be undergone FNAB(76.0% vs 55.3%, P=0.084), and ill-defined margin was more common in MTC nodules with cervical lymph node metastasis(36.4% vs 12.8%, P=0.009). Despite having a few US features closely linked to the malignant nodules such as solid, hypoechogenicity and with microcalcification, the MTC nodules also have specific US imaging characteristics as regular sharp, well-defined margin and AP/ TR<1.