[Neuroendocrine carcinoma of the larynx with secretion of calcitonin: primary tumor or metastasis of the medullary thyroid carcinoma?].

Neuroendocrine carcinomas of the larynx are rare and their links with thyroid neoplastic lesions are not specified in most reported cases. We report such a case secondary to medullary thyroid carcinoma. In a 63-year-old man, a supra glottic laryngeal carcinoma confirmed by biopsy was initially treated by chemotherapy. A second biopsy of the laryngeal lesion after incomplete remission displayed a neuroendocrine carcinoma with calcitonin in neoplastic cells. Laryngectomy, cervical bilateral neck dissection and thyroid isthmic adenoma dissection were performed. Numerous neoplastic cells from these tissues contained calcitonin revealed by immunohistochemical method. Calcitoninemia was highly increased and multiple bone metastases were discovered. Secondary total thyroidectomy was not possible and the patient died 6 months after. In this case the neuroendocrine laryngeal carcinoma was probably secondary to a latent medullary thyroid carcinoma. Medullary thyroid carcinoma is most often unknown in similar previously reported cases of neuroendocrine laryngeal carcinoma. Thus a neuroendocrine tumour of the larynx should require search for extra thyroid and over all thyroid neuroendocrine carcinoma, even limited to a small and latent lesion.