A 58-yrs-old presents with increased "fullness" in her neck. Examination finds non tender diffuse enlargement of her thyroid gland. Clinically she is euthyroid. Sections from her thyroid gland reveal numerous, mainly enlarged follicles, most of which are filled with abundant colloid material. There are areas of fibrosis, hemorrhage, and cystic degeneration. No papillary structures are identified and neither colloid scalloping nor Huhle cells are present. Most likely diagnosis is?
* Goiter is a general clinical term that is used to describe any enlargement of the thyroid. Most patients with goiter are euthyroid (nonfunctional goiter), as hypehyroidism (toxic goiter') is relatively rare, in the early stages of goiter formation, there is diffuse hyperplasia of the small thyroid follicles, which histologically resembles the changes of Graves disease. This early stage is called a diffuse nontoxic goiter or simple goiter. * The thyroid gland then undergoes repeated episodes of involution and hyperplasia. Over time this produces an enlarged multinodular goiter that histologically consists of multiple nodules, some of which consist of colloid-filled enlarged follicles and others of which show hyperplasia of small follicles lined by active epithelium. * There are also areas of fibrosis, hemorrhage, calcification, and cystic degeneration. The last stage of goiter formation consists of nodules composed primarily of enlarged colloid-filled follicles. This stage is called a colloid goiter. * In contrast to the histologiC appearance of multinodular or colloid goiter, diffuse toxic goiter (Graves' disease) is characterized by hyperplasia of the follicular cells with scalloping of colloid at the margin of follicles, while Hashimoto's thyroiditis has a marked Iymphoplasmacytic infiltrate with lymphoid follicles and scattered oxyphilic (Huhle) cells.
Colloid carcinoma
Diffuse toxic goiter
Graves disease
Multinodular goiter