Calcitonin-Secreting Neuroendocrine Carcinoma of Larynx with Metastasis to Thyroid.
Primary neuroendocrine tumors of the larynx are rare, with moderately differentiated neuroendocrine carcinoma (MDNC) being the most frequent histologic type. We report a MDNC in a 57-year-old gentleman with an enlarging right-sided neck mass. Flexible fiberoptic exam revealed a right arytenoid lesion. Histology from excisional biopsy was concerning for medullary thyroid carcinoma (MTC) versus NET of the larynx. Immunohistochemistry was diffusely positive for calcitonin and CEA and focally positive for TTF-1. Serum calcitonin was elevated. Thyroid ultrasound was unremarkable. The patient underwent laryngectomy, thyroidectomy, and neck dissection. Pathology showed neuroendocrine carcinoma of right arytenoid with positive cervical lymph nodes. A 4 mm deposit of NET was present in right thyroid with adjacent intravascular tumor consistent with thyroidal metastasis from a primary laryngeal NET (MDNC). MDNC and MTC can be microscopically indistinguishable. Both tumors can stain positively for calcitonin and CEA. TTF-1 staining has been useful to help distinguish these tumors as it is strongly and diffusely positive in MTC, but usually negative (or only focally positive) in MDNC. We report the fourth case of primary neuroendocrine carcinoma of the larynx associated with elevated serum calcitonin level and the first such case associated with metastasis to the thyroid.
Division of Endocrinology, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Oklahoma City VA Health Care Systems, Oklahoma City, OK 73104, USA.
Lauren
L
LaBryer
Oklahoma City VA Health Care Systems, Oklahoma City, OK 73104, USA ; Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
Ravindranauth
R
Sawh
Oklahoma City VA Health Care Systems, Oklahoma City, OK 73104, USA ; Department of Otolaryngology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
Colby
C
McLaurin
Division of Endocrinology, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Oklahoma City VA Health Care Systems, Oklahoma City, OK 73104, USA ; Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
R Hal
RH
Scofield