We report a case of right sus-clavicular lymph nodes metastasis which revealed a calcitonin secreting carcinoma in a 36 years old woman. Any tumor has been noted in the completely included thyroid gland. There was many lymph nodes metastasis in the right mediastinal removal. A pulmonary origin neuroendocrine carcinoma hyposthesis has been evoked. The outcome proved to be quickly fatal with cerebral metastasis occurrence. Extrathyroid calcitonin secreting carcinomas are rare. Then the discussion was founded on the diagnosis process in the face of hypercalcitoninemia, and on the calcitonin secretion by neuroendocrine cells and neoplasms of the lung.