Simple Cysts of the Thyroid

Author

The Common Vein Copyright 2010

Definition

A simple cyst is a benign epithelial fluid filled structure in the thyroid that shows no intenal mrphology and no intrinsic blood flow.  they may be congenital or acquired..

Thyroid Cyst

The diagram outlines a simple cyst pale yellow in the left lobe of the thyroid.

Courtesy Ashley Davidoff MD copyright 2010 all rights reserved 93852.d04.8s

Cyst in the Isthmus

The transverse ultrasound scan through the right lobe of the thryroid and isthmus shows a 7.3mms cyst on the right side of the isthmus (yellow in b). It is characterised by its anechoic nature, and a hint of throufgh transmission as seen as increased echoes behind the cyst. There is no definite backwall enhancement which is the other major characteristic of a cyst. Note the posterior relationship of the trachea (T). The right internal carotid artery is seen in red

Courtesy Ashley Davidoff MD copyright 2010 all rights reserved 77508c04.81s

Large (Almost Simple) Cyst

A large cyst occupies almost the entire left lobe of the thyroid gland is seen by ultrasound which in sagittal (a,b) measures 3.7cms and in A-P dimension measures 2,4cms(c,d). The cyst is characterised by anechogenicty, through transmission but no definite back wall enhancement. Two small calcifications are seen as white specks in the transverse view. The gland is compressed (salmon pink). These findings are characteristic of a large simple cyst of the gland.

Courtesy Barry Sacks MD Copyright 2010 97018c01.8

Thyroglossal Duct Cyst

The MRI T2 weighted image through the inferior aspect of the thyroid gland (pink) shows a cystic structure (yellow), intensely T2 bright (a), in the region of the isthmus in the ventral and midline position of the gland. Findings are consistent with a thyroglossal duct cyst

Courtesy Ashley Davidoff MD Copyright 2010 97310cL.8