adenomatous goiter:
The thyroid gland in adenomatous goiter is usually enlarged and becomes multinodular as being seen on outer surface and on cut surfaces. Each nodules are often partially to completely encased in fibrous septae or capsule. The nodules usually show quite variation in appearance from 1) semitranslucent colloid riched nodulesmay be with cystic degeneration , 2) hemorrhagic nodule, 3) colloid cyst, 4) nodule with fibrosis and calcification, and 5) hyperplastic nodule which show solid whitish cut surfaces. These change can be seen in spectrum and may not involve all the thyroid tissue and leave large areas of near normal thyroid tissue. 
Differential diagnosis: Toxic multinodular goiter (plummer's disease)
Hyperplastic nodule vs follicular neoplasm