INSM1 and medullary thyroid gland carcinoma: In the head and neck area, sinonasal neuroendocrine carcinoma, neuroendocrine carcinomas localized in the hypopharynx larynx trachea and parapharyngeal space as well as HPV-related neuroendocrine carcinomas, paraganglioma and medullary thyroid carcinoma, are shown to be immunoreactive for INSM1.