الفهرس 
AnatomyOnly 14 pages are availabe for public view
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Abstract
A folicular thyroid lesion comprises follicular adenoma and follicular carcinoma which can only be distinguished on histology of surgerical specimen by presence /absence of vascular and capsular invasion Some clinicians therefore prefer to use the collective term”follicular lesions” for both a benign follicular adenoma and a malignant follicular carcinoma.(Wong and Ahuja, 2005 )
Most follicular neoplasms are solid and in 70 % of cases, they are homogeneous in echogenicity They can be isoechoic, hyperechoic, hypoechoic, or mixed.Their shape is usually oval or round and sonographic appearance is very similar to a normal testicle. A thin hypoechoic halo is present in 80% of cases. Small focal cystic components may be present. Calcification is rare. Vascularity is usually diffusely increased through out the nodule. ( Reading et al, 2005 )
Ultrasound, in most cases, can not accurately distinguish a benign from malignant follicular lesions. The suspicion of malignancy is raised if the nodule is ill-defined , has a thick irregular capsule and chaotic intranodular vascularity.The only reliable signs of malignancy on ultrasound include frank vascular invasion to adjacent vessels and extracapsular spread . ( Wong and Ahuja, 2005 )
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