|Year : 2011 | Volume
| Issue : 2 | Page : 63-65
Well differentiated carcinoid tumor of the subglottis
Rohit Verma1, C Venkatakarthikeyan1, Rakesh Kumar1, Kapil Sikka1, Seema Kaushal2
1 Department of Otorhinolaryngology, Head and Neck Surgery, All India Institute of Medical Sciences, New Delhi, India
2 Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||19-Sep-2011|
Department of ENT, Head and Neck Surgery, All India Institute of Medical Sciences, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Neuroendocrine tumors of the larynx are rare, comprising only about 0.5% of laryngeal tumors. These tumors are characterized by pathological and biological heterogeneity. Well differentiated carcinoid tumor is the rarest variety of laryngeal neuroendocrine neoplasms. This tumor most commonly appears as a submucosal lesion of the supraglottic larynx. As per our knowledge, this tumor has never been reported in the subglottis. In this article we describe a rare case of a well-differentiated carcinoid tumor of the larynx involving the subglottis.
Keywords: Carcinoid, larynx, neuroendocrine tumor, subglottis
|How to cite this article:|
Verma R, Venkatakarthikeyan C, Kumar R, Sikka K, Kaushal S. Well differentiated carcinoid tumor of the subglottis. J Laryngol Voice 2011;1:63-5
| Introduction|| |
Neuroendocrine tumors (NETs) of the larynx represent a heterogeneous group of neoplasms. They were first recognized as a distinct clinical and pathologic entity by Goldman et al. Since then, approximately 450 cases have been reported in the English language literature, of which only 13 have been well-differentiated carcinoid tumors. The World Health Organization recognizes four categories:  typical/ well differentiated carcinoid tumor, atypical carcinoid tumor, small cell neuroendocrine carcinoma, and paraganglioma. The treatment and prognosis vary across these four categories, making the histological diagnosis crucial. In this article, we describe a rare case of a well differentiated carcinoid tumor of the larynx involving the subglottis.
| Case Report|| |
A 21 year old female presented to our emergency department with the complaint of severe breathing difficulty. She had this problem for the last 4 years, but it worsened significantly over the past one year. She had no complaints of change in voice, dysphagia or throat pain. Previously she had consulted multiple physicians and was being treated as a case of bronchial asthma. On presentation to our emergency department she had severe inspiratory strider. Rest of the clinical examination was within normal limits. Emergency tracheostomy was done under local anaesthesia to relieve the airway obstruction. Cervical computed tomography showed a well circumscribed intensely enhancing mass in the subglottis causing significant airway compromise [Figure 1]. There were no enlarged lymph nodes. Chest X- ray was normal. A 99m Tc- Pertechnetate labeled Red blood cell (RBC) blood pool scintigraphy was done to rule out the lesion being a hemangioma. No abnormal pooling was noted in the subglottic mass. Direct suspension laryngoscopy revealed mucosa covered mass in the subglottis on the left side from which biopsy was taken. The histopathological examination showed a tumor composed of monotonous population of small cells arranged in nests and forming rosettes. Immunohistochemistry was positive for neuron specific enolase [Figure 2] and chromogranin. The features were consistent with a well differentiated carcinoid. 24 hour urine 5- HIAA (5- hydroxyindoleacetic acid) levels were within normal limits. 68Ga DOTANOC Positron emission tomography - computed tomography (PET-CT) study was done which showed no significant 68Ga DOTANOC uptake by laryngeal mass. Rest of the body showed normal physiological radiotracer uptake. Patient subsequently underwent laryngofissure and excision of the tumor with placement of Montgomery tube under general anaesthesia. Post operative histopathological examination of the tumor was consistent with a well differentiated carcinoid tumor. Post operative period was uneventful with normal vocal cord function. Patient was successfully decannulated six weeks post operatively and is disease free after a follow up of two years.
|Figure 1: Contrast enhanced computed tomography scan of the neck (sagittal) showing intensely enhancing mass in the subglottis|
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|Figure 2: Tumor cells showing positivity for Neuron Specific Enolase (Immunoperoxidase x100)|
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| Discussion|| |
Carcinoid tumors were first recognized in 1907 by Oberndorfer, who distinguished them from other carcinomas. Although the respiratory tract is a common site of involvement, carcinoid of the larynx is exceedingly rare. In 1955, Blanchard and Saunders  reported the first description of laryngeal neuroendocrine tumor. Neuroendocrine neoplasms of the larynx have been categorized into 4 histologic types on the basis of the tissue of origin and the histopathological characteristics of the tumor as per World health Organization [Table 1]. The clinical behavior of these tumors and outcomes of treatment are directly related to the specific tumor type. Epithelial-origin neuroendocrine tumors of the larynx, such as typical carcinoid, arise from uncommitted epithelial stem cells that are capable of differentiating into multiple cell types. In contrast, neuroendocrine tumors of neural origin (paraganglioma) are derived from paraganglion cells located in proximity to the larynx. Although neuroendocrine neoplasms of the larynx contain neurosecretory components capable of producing a paraneoplastic syndrome, active tumor secretion is infrequent. 
|Table 1: World health organization classifi cation of neuroendocrine tumors of larynx based on histology|
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In terms of clinical presentation, laryngeal neuroendocrine tumors occur predominantly in men during their sixth decade of life. Presenting symptoms are typical of a laryngeal mass and include dysphagia, odynophagia, globus sensation, and sometimes aspiration. Neuroendocrine tumors of the larynx have a predilection for the supraglottis because this area is rich with neuroendocrine cells. Primary involvement of the subglottis is not common.
Typical carcinoid is the least common of the laryngeal neuroendocrine tumors with only 13 cases reported to date. It often appears as a submucosal lesion of the supraglottic larynx, in the form of a polyp or a sessile lesion. The typical patient is a man (3:1 male-to-female ratio) in the sixth to eighth decade of life who has a history of smoking.  Histologically, the tumor shows organoid formations of cells that are monotonous, with scanty clear or eosinophilic cytoplasm. The defining characteristics of the typical carcinoid tumor are the absence of pleomorphism, necrosis, or invasion, and only rare mitotic figures. Immunohistochemistry shows positive staining for neuron specific enolase, chromogranin, serotonin, and cytokeratin.  Computed tomography of the larynx is useful for evaluating local and regional tumor spread. Conservative surgery is the treatment of choice. Neck dissection is not mandatory since this well-differentiated and slowly growing tumor rarely metastasizes to the lymph nodes. The prognosis is excellent provided the margins are tumor-free. 
| Conclusion|| |
Neuroendocrine tumors of the larynx are a heterogenous group of neoplasms as far as their pathological features and biological behavior is concerned. They require an accurate histopathological diagnosis because of their varied clinical behavior and response to treatment. The prognosis for these unusual laryngeal neoplasms ranges from favorable to poor, depending on the specific tumor type. Typical carcinoid tumor of the larynx is a rare malignancy characterized by slow growth and limited aggressiveness. The treatment is usually conservative and the prognosis excellent.
| Acknowledgement|| |
Authors deeply acknowledge the contribution of Prof. R.C Deka, Director, All India Institute of Medical Sciences for his kind support and guidance
| References|| |
|1.||Goldman NC, Hood CI, Singleton GP. Carcinoid of the larynx. Arch Otolaryngol 1969;90:64-7 |
|2.||Shanmugaratnam K., Sobin L. H. Histological typing of tumours of the upper respiratory tract and ear. 2 nd ed. Heidelberg: Springer-Verlag, 1991. |
|3.||Blanchard CL, Saunders WH. Chemodectoma of the larynx: A case report. Ama Arch Otolaryngol 1955;61:472-4. |
|4.||Ferlito A, Rosai J. Terminology and classification of neuroendocrine neoplasms of the larynx. ORL J Otorhinolaryngol Relat Spec 1991;53:185-7. |
|5.||El-Naggar AK, Batsakis JG. Carcinoid tumor of the larynx. Actual review of the literature. ORL J Otorhinolaryngol Relat Spec 1991;53:188-93. |
|6.||Soja J, Osaka M, Yakuma Y. Laryngeal endocrinomas (carcinoid and relevant neoplasms): Analysis of 278 reported cases. J Exp Clin Cancer Res 2002;21:5-13. |
|7.||Ferlito A, Barnes L, Rinaldo A, Gnepp DR, Milroy. A review of neuroendocrine neoplasms of the larynx: Update on diagnosis and treatment. J Laryngol Otol 1998;112:827-34. |
[Figure 1], [Figure 2]