What are thyroid adenomas?

Usually follicular origin (follicular adenomas), often solitary, well limited and capsulated, compresses surrounding nonneoplastic thyroid tissues, well-defined intact capsule. Average size 3 cm, color from red to gray-white, areas of remodeling may exist. Microscopy (different architecture than surrounding thyroid tissue, regular cells/few mitoses, may get cutonuclear atypica but not sx of malignancy on their own, so when we see atypical signs (very rapid division, hypercells, atypia) we look at capsule if invaded/vascular invasion to differentiate it from carcinoma.