esophagogastroduodenoscopy ( egd ) is a common and established procedure for the diagnosis , follow - up , and treatment of a variety of upper gastrointestinal ( gi ) tract disorders including gastric neoplasm.1,2 ) the incidence of stomach cancer is high in east asian countries including china and south korea,3,4 ) compared to western countries in europe and north america . in south korea , stomach cancer is the second most common cancer and third most common cause of cancer death.5 ) additionally , the cost of egd is relatively low at approximately $ 60 us per endoscopic examination . thus , screening upper gi endoscopy is widely performed in this east asian country.5,6,7 ) however , the number of gastroenterologic specialists is not sufficient to meet the growing demand . consequently , family physicians have contributed to meeting this demand by performing egd.8,9,10 ) the primary focus of egd is the examination of the esophagus , stomach , and proximal duodenum ( usually till 2nd portion).11 ) however , oral cavity , pharynx , and larynx including the epiglottis may also be observed during the insertion and withdrawal of the endoscope ( figure 1 ) . therefore , diverse non - upper gi lesions may be encountered during egd.12 ) in this report , we present a 55 year - old - patient with an asymptomatic epiglottic cyst incidentally found during screening endoscopy , along with a review of the relevant literature . an asymptomatic 55-year - old woman with a family history of gastric cancer visited at the department of family practice and community health , ajou university hospital for routine medical check - up including a screening egd for upper gi cancer . she had hypertension that was controlled with medication , and had no other medical illness or surgical history . the patient was healthy - looking in appearance , but obese ( height , 160.3 cm ; weight , 71.1 kg , waist circumference 101.2 cm ; body mass index , 27.7 kg / m ) . the patient 's vital signs showed a blood pressure of 115/70 mm hg , a regular heart rate of 70 beats / min , a respiratory rate of 18 rates / min , and a body temperature of 36.7. other aspects of the physical examination including abdomen were unremarkable as well . all laboratory tests such as complete blood cell counts , aspartate aminotransferase , alanine aminotransferase , protein , albumin , electrolyte , blood urea nitrogen , creatinine , lipid panel ( total cholesterol , triglyceride , high density lipoprotein cholesterol , and low density lipoprotein cholesterol ) , fasting glucose , urine analysis , and stool examination were all within normal limits . radiologic evaluations including chest x - ray , abdomen supine / erect x - ray , and abdominal ultrasonography were also without significant findings . two years previous to this egd , the patient had undergone screening egd with sedation , which was without significant findings or complications . at this time , she wanted egd with sedation in order to avoid discomfort and anxiety about the procedure . thus , we decided to perform egd under conscious sedation , and written informed consent was obtained from the patient . after fasting for 12 hours ( nothing by mouth after dinner the day before the egd ) , the egd was commenced the next morning . first , 10% lidocaine ( xylocaine spray ; astrazeneca korea pharmaceutical co. , seoul , korea ) was sprayed as local pharyngolaryngeal anesthesia . the egd was performed under conscious sedation with combinations of intravenous midazolam ( dormicum ; roche korea pharmaceutical co. , seoul , korea ) and propofol ( pofol ; jeil pharmaceutical co. , seoul , korea ) . in addition , an antispasmodic agent , cimetropium bromide ( algiron ; green - cross pharmaceutical co. , yongin , korea ) , was given intravenously immediately before the procedure to minimize upper gi movements , which can interfere with detailed and complete inspection . the endoscopist performed the procedure on the patient with an olympus gif - h260 video endoscope ( olympus optical co. , ltd . , tokyo , japan ) . during the procedure , blood pressure , pulse , and oxygen saturation were monitored . when the endoscope was intubated into the oral cavity ( figure 2a - c ) , an approximately 15  30 mm sized globular yellowish cystic mass with smooth surface and visible vessels was seen arising from the right side of epiglottis ( figure 2d , e ) . both the left and right vocal cords were intact , well - mobile , and free of adhesions ( figure 2f , g ) . also , the lesion did not interrupt the advance of the endoscope , which was inserted through piriformis fossa ( figure 2h ) into the esophagus ( figure 2i ) . the remainder of the examination was without abnormal findings except for mild chronic superficial gastritis in the antrum . although the patient was asymptomatic , the patient was referred to the otolaryngology department because of the accelerated growth of the lesion to a relatively large size within a 2 year period and the possibility of airway obstruction and difficulty in intubation in future emergency situations . the cystic - like mass was resected by carbon dioxide ( co2 ) laser under operating micro - laryngoscope ( figure 3 ) and sent for histopathology , after which the lesion was confirmed to be a benign epiglottic cyst . on hematoxylin and eosin stain , the cyst was lined by columnar to cuboidal epithelium without lymphoid infiltration ( figure 4a , b ) . the patient tolerated the procedure well , and the post - operative course was uneventful . laryngeal cyst is a rare entity and constitutes only 4.3% to 6% of all benign laryngeal tumors.13 ) in 1852 , verneuil first described the presence of a laryngeal cyst in a post - mortem of an infant.14 ) also , in 1864 , durham15 ) first reported a case of epiglottic cyst in an 11-year - old boy , which was successfully treated by surgical incision . since then , a variety of cases have been reported , but the laryngeal cysts , including epiglottic variants , still present a relatively rare occurrence . the larynx extends vertically from the tip of the epiglottis to the inferior border of the cricoid cartilage , i.e. , the entrance of the trachea . the function of the larynx is involved in breathing , sound production ( phonation ) , and protection of the trachea against food aspiration . the epiglottis is one of nine cartilaginous structures that make up the larynx ; the laryngeal skeleton consist of nine cartilage structures , three single ( epiglottic , thyroid , cricoid ) and three paired ( arytenoid , corniculate , cuneiform ) ( figure 1 ) . epiglottic cysts arise in the region of epiglottis , a thin valve - like structure made of cartilage that is located behind the base of tongue . henderson et al . demonstrated that 52% of the laryngeal cysts originated from the lingual aspect of the epiglottis in their study.16 ) in our case , the lesions were discovered on the lingual surface of the epiglottis as well . epiglottic cyst seems to be more prevalent in the 6th decade of life , which was the case in this patient , although they can affect and have been reported in all ages.13 ) because the diameter of the respiratory tract is smaller in infants and children , an epiglottic cyst may easily obstruct the airway in this age group , and sufficiently large cysts may present as stridor , cyanosis with feeding , respiratory difficulty , and have the potential to be life - threatening . however , most adult epiglottic cysts are benign and asymptomatic.17 ) therefore , these anomalies are sometimes discovered unintentionally during routine otolaryngological examination , induction of general anesthesia , and upper gi endoscopy , because this area is the passage to going into the esophagus during endoscopic examination . in our case , the lesion was incidentally found during screening endoscopy for gastric cancer , and the patient had been asymptomatic and unaware of the lesion . however , in accordance with the size and extension into the airway , there were symptoms associated these lesions such as foreign body sensation in the throat , hoarseness , cough , stridor , and dysphagia . additionally , epiglottic cyst may have a future risk of airway obstruction.17,18 ) for example , during induction of anesthesia , asymptomatic and undiagnosed epiglottic cyst may cause the development of respiratory failure when muscular relaxation may drive cysts into the larynx causing partial or complete obstruction , which may lead to unanticipated difficulty in ventilation or intubation or both.19 ) thus , lesions can be potentially life - threatening and may require tracheostomy in emergency situations . this may progress to the epiglottitis and epiglottic abscess , which can also be a cause of airway obstruction and respiratory arrest.20,21,22 ) thus , early intervention may be prudent for incidentally found epiglottic cyst in adults , though they may be symptomless and small in size . treatment options include endoscopic excision , marsupialization , unroofing , and lateral pharyngotomy.23,24,25 ) recently , co2 laser has been successfully applied in nearly all cases due to superior coagulation of the laser and shorter time to recovery.16,22,26 ) simple aspiration is no longer recommended due to high recurrence rates,27 ) but can be used for volume reduction prior to surgical or co2 laser resection . in our case , the epiglottic cyst of our patient was completely removed using co2 laser under operating micro - laryngoscope without complications . local recurrence of epiglottic cysts can be minimized by complete removal of the cyst wall . in certain cases , prophylatic antibiotics may occasionally be helpful after treatment to avoid acute epiglottitis.28 ) there are a variety of pathohistological classifications of laryngeal cysts including epiglottic cysts . in 1922 , myerson classified these cysts into retention , embryonic , vascular , and traumatic types.29 ) however , this classification was complex and impractical . in 1970 , desanto et al.30 ) divided these anomalies into two types : 1 ) ductal - type and 2 ) saccular - type . the ductal - type was considered to be caused by the obstruction of excretory duct of submucosal glands ; whereas the saccular - type was considered to have developed as a result of excessive extension of the saccule of the ventricular fold in the larynx . in a histologic study published in 1984 , newman et al.31 ) categorized the lesions according into three types : 1 ) epithelial - type , 2 ) tonsillar - type , and 3 ) oncocytic - type . in our case , the lesion was of ductal - type by desanto classification and epithelial type by newman 's histologic classification . since its first introduction in early 19th , egd has been accepted as the best tool for the diagnosis and follow - up of upper gi disorders , including screening of gastric neoplasms . therefore , the demand for egd continues to grow worldwide , especially in asian countries where the incidence of gastric cancer is comparatively high . during egd , the endoscopists ' main focus of examination is the esophagus , stomach , and duodenum bulb and 2nd portion . however , incidental upper airway lesions can be identified in the pharynx and larynx , including those of the epiglottis and vocal cords , during the insertion and withdrawal of the endoscope into and from the esophagus . these lesions of the pharynx and larynx may be of malignant neoplasms or pathologic lesions with malignant potential . additionally , even though such a lesion is benign , it may represent a future risk of complications , as deemed for the patient in our case . therefore , this area should also be examined thoroughly during insertion as well as withdrawal of endoscope . also , if a lesion is incidentally discovered in the area , proper and careful judgment by the endoscopist ( follow - up versus further work - up versus immediate intervention including referral to other department ) with regard to the patient is required .
from the endoscopists ' point of view , although the main focus of upper gastrointestinal endoscopic examination is the esophagus , stomach , and duodenum ( usually bulb and 2nd portion including ampulla of vater ) , the portions of the upper airway may also be observed during insertion and withdrawal of the endoscope , such as pharynx and larynx . 
 thus , a variety of pathologic lesions of the upper airway can be encountered during upper endoscopy . among these lesions , 
 an epiglottic cyst is relatively uncommon . 
 the cyst has no malignant potential and mostly remains asymptomatic in adults . 
 however , if large enough , epiglottic cysts can compromise the airway and can be potentially life - threatening when an emergency endotracheal intubation is needed . 
 thus , patients may benefit from early detection and treatment of these relatively asymptomatic lesions . in this report 
 , we present a case of epiglottic cyst in an asymptomatic adult incidentally found by family physician during screening endoscopy , which was successfully removed without complication , using a laryngoscopic carbon dioxide laser .