Which type of cancer is associated with "Orphan Annie" eye nuclei?

"Orphan Annie" eye nuclei are characteristic of papillary carcinoma of the thyroid. This distinctive feature refers to the appearance of the nuclei that are large, empty-appearing, and have an irregular contour, resembling the eyes of the cartoon character Orphan Annie. This finding is primarily due to the presence of intranuclear cytoplasmic inclusions and is a classic histopathological hallmark of this type of thyroid cancer.

Papillary thyroid carcinoma is the most common type of thyroid malignancy and often arises from follicular cells. It is also typically associated with other features like psammoma bodies and a tendency for metastasis to cervical lymph nodes. Recognizing these histological features in tissue samples is crucial for diagnosis and understanding the prognosis of the disease.

In contrast, medullary thyroid carcinoma is derived from parafollicular C cells and is associated with a different histological profile, while follicular thyroid carcinoma and follicular adenoma also present with follicular patterns but lack the characteristic nuclear features seen in papillary carcinoma. Hence, the presence of "Orphan Annie" eye nuclei is a defining characteristic that helps in accurately diagnosing papillary carcinoma of the thyroid.