Ultrasonographic features and clinicopathologic characteristics of macrofollicular variant papillary thyroid carcinoma

Macrofollicular variant papillary thyroid carcinoma (MFV-PTC) is defined as papillary thyroid carcinoma with macrofollicles of >200 μm in more than 50% of the cross-sectional area of the specimen. The aim of this study was to evaluate the clinicopathologic characteristics of the MFV-PTC treated in the Yonsei University College of Medicine. Between September 2007 and July 2012, 18,697 patients with PTC were treated in our institution. Of these, 10 patients (0.05%) were diagnosed as the MFV-PTC in final pathologic report. Mean age of 10 patients were 42.5 years old, ranging from 26 to 69 years. Twelve lesions were found in 10 patients. On preoperative ultrasonographic examination, most of tumors looked like benign nodules. The tumor nodules varied in size from 0.3 to 3.5 cm in greatest dimension. Microscopically, the macrofollicles were surrounded by cuboidal cells with hyperchromatic nuclei and occupied entire nodule. MFV-PTC showed the benign appearance in ultrasonography. To avoid misdiagnosis of MFV-PTC, clinicians should be aware of the characteristics of MFV-PTC and perform ultrasonography with fine needle aspiration biopsy appropriately.