Pathology of the Head and Neck

Larynx and Hypopharynx Chapter 7 211The depth of the ulcers may vary from superficial todeep lesions extending down to the perichondrium ofthe arytenoid cartilage. The localised necrosis of the epithelialand subepithelial tissue triggers an acute inflammatoryreaction, with proliferation of granulation tissueinitially infiltrated by neutrophils and later by macrophages,lymphocytes and plasma cells (Fig. 7.7b) . Themarginal epithelium starts to proliferate, some regenerativeatypia of epithelial cells, such as plump nuclei, andincreased mitoses may be present [217, 383].An exuberant proliferation of granulation tissueforms an exophytic polypoid lesion . New vessels arecharacteristically arranged radially from the base tothe fibrin-covered surface of the lesion. Approximately1 week after the initial injury, connective cells and collagenousfibres become more abundant and finally thepredominant elements in the granuloma, which in theend stage is entirely covered in squamous epithelium .The covering epithelium is usually considerably thickeneddue to hyperplasia of the prickle cell layer or, rarely,of the basal and parabasal layer [177, 180].The basis of therapy in CU/CGs and hyperacidicgranulomas is the elimination of causative factors, voicerest , voice re-education , dietary measures , prohibitionof smoking and alcohol abuse , and medical therapy suchas antacids , corticosteroids and vitamins [224]. IGs frequentlydo not require treatment due to their self-limitingnature. In refractory cases, surgical treatment is indicated,either microsurgery or CO 2 laser [28].7.5.3 NecrotisingSialometaplasiaNecrotising sialometaplasia (NS) is a rare, benign, selfhealinginflammatory lesion involving the minor salivaryglands, primarily of the hard palate. The lesion isdiscussed in detail in Chap. 5. Here, some specificitiesof the extremely rare appearance of NS in the larynx arepresented [373, 380, 383]. According to previous reports[373, 380], as well as our own experience, NS occurs inthe larynx secondary to trauma or concomitantly withother non-neoplastic or neoplastic lesions. The pathogenesisis probably associated with ischaemia. Laryngeal NSappears in the supraglottic and subglottic regions whereseromucinous glands are present as a deep ulcerative orsubmucosal nodular lesion. The most prominent histologiccharacteristics that help to distinguish the lesion fromvarious forms of laryngeal carcinomas are: preservationof the lobular architecture of the necrotic glandular islands,the appearance of epithelial-myoepithelial islandswith smooth margins, no cellular atypia or occurrence ofpathologic mitoses in the rest of the cellular part, and theretention of the lumina in preserved ductal formations.The appearance of surface pseudoepitheliomatous hyperplasiamay cause additional problems in differentialdiagnosis with laryngeal cancers, especially when frozensection analysis is performed. The duration of the healingprocess is related to the size of the lesion [380].7.5.4 Metaplastic ElasticCartilaginous NodulesMetaplastic elastic cartilaginous nodules (MECN) aresmall (less than 1 cm) fibroelastic lesions occurringmost frequently in the posterior and mid-portions of theglottis and ventricular bands. Cartilaginous nodules arecomposed of a peripheral rim of fibroblasts with transitioninto fibroelastic cartilage towards the centre [112].Aetiologically, an association with laryngeal trauma hasbeen suggested [277]. The development of MECN showsa smooth transition from the initial accumulation of acidmucopolysaccharides between the collagen bundles andtheir separation, to transition of fibroblasts to enlarged,rounded cells resembling chondrocytes. Aggregates ofelastic fibres are present in the centre of the lesions [156].Nodules are usually covered by intact mucosa.Metaplastic elastic cartilaginous nodules are rarelyclinically relevant [277]. We should be aware of theirpossible existence and distinction from chondroma andlow-grade chondrosarcoma. Chondroma has a characteristiclobular pattern and low cellularity, which is notthe case with MECN. Low-grade chondrosarcomas differmainly from MECN in their locations, and cellularand structural atypia [277].7.5.5 AmyloidosisAmyloidosis is a heterogeneous group of disorders associatedwith extracellular deposition of an abnormalfibrillar protein with pathognomonic tinctorial properties.It may be hereditary or acquired, localised or systemicin distribution. The current classification of amyloidosisis based on the biochemical composition of itspeptide subunits [131].Laryngeal amyloidosis (LA) is rare and is mostly a localiseddisease. In the majority of LA cases, the amyloid iscomposed of immunoglobulin light chains (AL amyloid).LA may occasionally be part of systemic disease or can be associatedwith a tumour, such as neuroendocrine carcinomaof the larynx or medullary carcinoma of the thyroid [359].Laryngeal amyloidosis primarily affects patients between40 and 60 years of age, more frequently males[298]. A few cases have been reported in children [273].All parts of the larynx can be affected [359], but in somestudies the supraglottis was the most common site of involvement[159]. It can affect the larynx multifocally,and can also extend to the tracheobronchial tree. Themain symptom is hoarseness, in some patients accompaniedby dysphagia, dyspnoea, or haemoptysis [159].