A goiter is an enlarged thyroid gland, which is a butterfly shaped gland in the neck.
It is located here (click the blue link for a picture).http://pathologyproject.files.wordpress.com/2011/04/normal1.gif
A goiter can occur for several reasons--for example, the thyroid may be overactive or it may be underactive.
A goiter does not produce one lump, however, as you are describing.
You may have a thyroid nodule if it is located in the area of the thyroid gland.
Thyroid nodules can be solid or fluid filled..and they can produce thyroid hormone or be cystic.
If you have a lump in the neck, your doctor will first do an exam. Then, if there is a question as to what the lump is, an ultrasound of the neck may be ordered along with blood tests and possible, if a thyroid nodule, a biopsy.
Please feel free to ask any follow up questions,
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