Pathology of the Head and Neck

Larynx and Hypopharynx Chapter 7 1997.2 Laryngocele,Cysts, Heterotopia7.2.1 General ConsiderationsA laryngocele is a rare congenital or acquired laryngeallesion that appears within and around the laryngeal saccule.Laryngeal cysts account for approximately 5% ofbenign laryngeal lesions [177, 265]. DeSanto presenteda classification of laryngeal cysts in which the lesionswere divided into ductal, saccular and thyroid cartilageforaminal cysts [80]. This classification, which ismore clinically adjusted, is based on the intramucosaldepth of the cyst and its location. Newman and coworkersfound it difficult to apply and proposed a newone, dividing the lesions into tonsillar, epithelial (saccularand ductal) and oncocytic cysts. According to theoriginal article, more than half of all laryngeal cystswere epithelial, one quarter tonsillar and less than 15%oncocytic [265].7.2.2 LaryngoceleLaryngocele is defined as an excessive elongation anddilatation of the air-filled laryngeal saccule (ventricularappendix), which communicates directly with the laryngeallumen. According to its site, there are three types oflesions: internal, external, and mixed. An internal laryngoceleextends in a superior-posterior direction, towardsthe area of the false vocal cord and aryepiglottic fold. Anexternal one expands cranially and laterally to the neckthrough the weak zone of the thyrohyoid membrane.It presents as a lateral neck mass that varies in size dependingon variations of the intralaryngeal pressure. Amixed or combined form has both internal and externalcomponents with a swelling of the neck and endolaryngealbulging [14, 15, 53]. The combined laryngocele isthe most common (44%), followed by internal (30%) andexternal (26%) forms [50].A laryngocele is quite a rare lesion, occurring ascongenital [60] or acquired, most frequently observedin infants and adults between 50 and 60 years. A malepredominance is evident with a ratio of 7:1 [227, 287].Most laryngoceles are unilateral. Aetiologically, thelesion occurs in persons with a congenital large sacculeand weakness of the periventricular soft tissue.In adults, various conditions involving a repeatedincrease in intralaryngeal pressure, such as inflictingglass-blowers, wind instrument musicians, singers,professional speakers, and patients with a chroniccough, are reported [227]. Stenosis of the saccule neck,which functions as a valve system, may also lead tothe occurrence of a laryngocele. The leading symptomsof an internal or compound lesion are hoarseness,cough, dyspnoea, dysphagia, and the sensationof a foreign body.The lesion may, however, be also asymptomatic in approximately12% of the cases [62]. The diagnosis is establishedby the history, and by physical and radiologicalexamination, especially computed tomography (CT).Histologically, a cystic extension of the saccule is evidentand its wall tends to lose its folded surface. The laryngoceleis covered by the respiratory epithelium; occasionallyan oncocytic or cuboidal metaplasia is present.Focally, chronic mononuclear inflammatory cellsare seen in the subepithelial stroma. Laryngocele-relatedcomplications include infection (laryngopyocele),aspiration and subsequent pneumonia [287]. There isalso a relationship between laryngocele and laryngealsquamous cell carcinoma in 4.9 to 28.8% of cases [140].The endoscopic surgical treatment of laryngocele is themethod of choice [354].7.2.3 Saccular CystA saccular cyst (SC) is a mucus-filled dilatation of thelaryngeal saccule that has no communication with thelaryngeal lumen [80, 161]. Most SCs are congenital inorigin; some may also appear as acquired lesions causedby various inflammatory processes, traumatic events,or tumours [1, 161, 257]. SCs, which may occur at anyage, are divided into anterior and lateral. The formerspread medially and posteriorly, and protrude into thelaryngeal lumen between the true and false vocal cord.The latter are generally larger and extend towards thefalse vocal cord and aryepiglottic fold. They may rarelyspread through the thyrohyoid membrane [10, 80, 161,357]. SCs may be asymptomatic, but the most commonsymptoms are progressive cough, dysphagia, hoarseness,dyspnoea and foreign body sensation. Diagnosisis often made by laryngoscopy combined with CT scan[69].Histologically, SCs are lined with ciliated respiratoryepithelium . An increased number of goblet cells may bepresent. Rarely, the cysts are partially or entirely linedby metaplastic squamous or oncocytic epithelium. Subepithelialstroma, i.e. the cyst wall, usually contains focallymphocytic infiltrates [177].Treatment is surgical, the decision on an endoscopicor an external approach depends on the type and size ofthe cyst, as well as the individual patient’s condition.7.2.4 Ductal CystDuctal cysts (DCs) are the most common laryngeal cystsand comprise up to 62.5% of all laryngeal cystic lesions.The characteristic retention of mucus in the dilated collectingducts of the intramucosal seromucinous glands