Lack of BRAF mutations in hyalinizing trabecular neoplasm.
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.
Baloch
Zubair W
ZW
Departments of Pathology and Laboratory Medicine, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.
Puttaswamy
Kanchan
K
Department of Otorhinolaryngology, 3400 Spruce Street, University of Pennsylvania Medical Center, Philadelphia, PA, 19104, USA.
Brose
Marcia
M
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.
LiVolsi
Virginia A
VA
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.