Multicentric encapsulated papillary oncocytic neoplasm of the thyroid: A case diagnosed by a combined cytological, histological, immunohistochemical, and molecular approach

Fine-needle aspiration (FNA) diagnosis of oncocytic lesions is challenging. In fact, oncocytic changes occur in inflammatory, hyperplastic, and neoplastic settings, including both benign and malignant tumors. The rare oncocytic variant of papillary thyroid carcinoma (PTC), shows papillae composed by cells with large oncocytic granular cytoplasm featuring clear PTC nuclear features. A morphological similar, but biologically distinct lesion, is the encapsulated papillary oncocytic neoplasia. Here, we first report on FNA, its cytological features together with histological, immunohistochemical, and molecular correlates. Diagn. Cytopathol. 2011;. (C) 2011 Wiley-Liss, Inc.