Enlarged thyroid cells with ground-glass nuclei are primarily associated with what condition?

Enlarged thyroid cells exhibiting ground-glass nuclei, often described as "Orphan Annie eye" nuclei due to their distinctive appearance, are primarily associated with papillary thyroid carcinoma. This type of cancer is the most common form of thyroid malignancy and has a characteristic histological pattern.

The ground-glass appearance of the nuclei arises from the disintegration of nucleoprotein structure within the nucleus, leading to a clear and finely reticular appearance. Papillary thyroid carcinoma often also demonstrates other features such as papillary structures and psammoma bodies, but it is the presence of these unique nuclei that serves as a hallmark for diagnosis.

The other conditions mentioned do not present with this specific nuclear morphology. Thyroid adenomas are typically benign and do not exhibit the characteristic nuclear features of malignancy. Follicular thyroid carcinoma shows a different histological pattern with solid and microfollicular architectures without the ground-glass nuclei. Medullary thyroid carcinoma, arising from parafollicular C cells, is characterized by neuroendocrine features rather than the distinctive nuclear changes seen in papillary thyroid carcinoma.

Therefore, the presence of enlarged thyroid cells with ground-glass nuclei is a defining characteristic of papillary thyroid carcinoma, making it the correct association in