Discussion
We describe a rare case of laryngeal NEN in subglottic. While many
laryngeal neuroendocrine carcinomas found in the supraglottic, in about
60 to 96 percent of casese.4
Although primary neuroendocrine carcinomas are rare, they are the most
common non-squamous neoplasm of the larynx. Based on 2017 WHO
Classification of Head and Neck Tumors, neuroendocrine tumors of the
larynx are classified as well-differentiated neuroendocrine carcinoma:
typical carcinoid; moderately differentiated neuroendocrine carcinoma:
atypical carcinoid; poorly differentiated neuroendocrine carcinoma:
small and large cell neuroendocrine carcinoma, and paragangliomas which
have a neural origin. Moreover, based on Neuroendocrine carcinoma (NEC)
classification as suggested by the International Agency for Research on
Cancer (IARC) and World Health Organization (WHO), in poorly
differentiated epithelial neoplasms, Microscopic histopathologic
analysis showing tumor necrosis, and mitotic rate of > 10/2
mm2.5
Atypical carcinoid is the most common neuroendocrine carcinomas of the
larynx that represents 0.2% - 0.6% of laryngeal malignancies.3, 5Also, atypical carcinoid has more aggressive
character that metastasis to cervical lymph nodes, bone, skin, liver,
and lung are frequent in their disease nature .6,7Laryngeal NENs typically affect middle-aged patients with a history of
heavy smoking with a male preponderance.8The common
clinical manifestations are Hoarseness, dysphagia, and sore throat. In
rare cases paraneoplastic syndrome happens. Moreover, cervical lymph
node metastases and cutaneous metastases may detect in some
cases.9
With this in mind, treatment and prognosis of the various NEC groups
differ; precise identification of tumor group is critical. Although,
surgery is usually the treatment for all tumor type, chemotherapy may be
utilized for moderately to poor differentiated NECs. Laryngeal
well-differentiated NEC is treated with wide local excision, generally a
partial laryngectomy, without neck dissection. While, in moderately
differentiated NECs partial or total laryngectomy with elective or
therapeutic neck dissection is necessary. However, adjuvant chemo
radiotherapy may be beneficial in some case. Eventually, chemo
radiotherapy is recommended for poorly differentiated NECs because
surgery is ineffective in these group.10Furthermore,
tumor prognosis differs among various tumors types. A 5-year
disease-specific survival rate is about100%, 53%, 19%, and 15%, in
Well-differentiated NEC, Moderately differentiated NEC, small cell NEC,
and large cell NEC respectively.4