Neuroendocrine carcinoma of the larynx with Lambert-Eaton myasthenic syndrome: a rare case report and literature review

This current report describes a rare clinical case of neuroendocrine carcinoma (NEC) of the larynx with associated Lambert-Eaton myasthenic paraneoplastic syndrome (LEMS). A 68-year-old male patient presented with severe dysphonia and dysphagia. He underwent a total laryngectomy and the excised lesion was extremely large. A pathological examination demonstrated 'morphological findings of a poorly differentiated carcinoma (G3) with aspects of neuroendocrine differentiation' (i.e. a poorly differentiated neuroendocrine carcinomas [PD-NEC]). Based on the patient's medical history and the immunohistochemical findings, he was treated with three cycles of neoadjuvant chemotherapy (cisplatin-etoposide) and then radiotherapy with a total dose of 70 Gy. Of the 10 cases of paraneoplastic syndrome (PNS) related to laryngeal NEC reported in the literature, nine of these syndromes were of an endocrine type. Only one case of PNS associated with laryngeal cancer had a neurological manifestation, which was LEMS. To the best of our knowledge, this current case has only one similar precedent in the literature and it is the second report of an association between a PD-NEC and LEMS. Laryngeal NECs are rare lesions with different prognostic characteristics. The diagnosis should be made using an endocrinological, neurological, radiological and histological multidisciplinary approach. A radical surgical approach is recommended.