title: Lack of BRAF mutations in hyalinizing trabecular neoplasm.
abstract: The hyalinizing trabecular neoplasm (HTN) of the thyroid is an unusual and controversial lesion. Some consider it a peculiar type of papillary thyroid carcinoma (PTC) because of its nuclear features and presence of psammoma bodies. Others consider it an adenoma. Molecular studies have found RET/PTC translocations in some examples, supporting HTN as a PTC; however mutations in BRAF (another marker for PTC) have not been found. We report two cases of classic HTN and a case of trabecular PTC and show BRAF mutations in the latter and not in HTN. Trabecular growth pattern is insufficient for a diagnosis of HTN and lesions with such a pattern and nuclear features of PTC are cancers. Morphologically classic HTN are not associated with metastatic potential and should be considered adenomas.
authors.affiliation: Departments of Pathology and Laboratory Medicine, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.
authors.forename: Zubair W
authors.initials: ZW
authors.lastname: Baloch
authors.affiliation: Department of Otorhinolaryngology, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.
authors.forename: Kanchan
authors.initials: K
authors.lastname: Puttaswamy
authors.affiliation: Department of Hematology & Oncology, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.|Department of Otorhinolaryngology, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.
authors.forename: Marcia
authors.initials: M
authors.lastname: Brose
authors.affiliation: Departments of Pathology and Laboratory Medicine, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.|Department of Otorhinolaryngology, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.
authors.forename: Virginia A
authors.initials: VA
authors.lastname: LiVolsi