Pathology of the Head and Neck

184 S. Regauer6ery and within the submucosa of the pharyngeal tonsilare a normal finding. The tubal tonsils are poorly definedcondensations of lymphoid tissue located aroundthe auditory tube in the nasopharynx and around thefossa of Rosenmüller. The term lingual tonsil refers to theabundant non-encapsulated lymphoid tissue in the adultposterior tongue. The crypts do not appear until birth,are shallow and much less branched than in the palatinetonsil. The surface is covered by non-keratinising squamousepithelium. Adipose tissue and skeletal muscle fibresat the base of the lingual tonsil, and mucous salivaryglands and lymph follicles within the lingual tonsilare integral parts of the tongue. Efferent lymphaticvessels of the posterior tongue drain into the deep cervicallymph nodes, after they pass through the pharyngealwall in front of or behind the external carotid artery[41].6.3.2 Congenital Anomaliesof Waldeyer’s RingCongenital anomalies include the extremely rare absenceof palatine tonsils and accessory tonsils within theoral cavity [68, 155]. Slightly more common is the “hairypolyp”, a choristoma, which arises from remnants of theectodermal and mesodermal germ layers in the palatinetonsil and nasopharynx (see also Sect. 6.2.3.2). The unilateralpedunculated hairy polyps of up to 5 cm arisemostly on the superior pole of the palatine tonsil andpresent with acute respiratory distress [129]. A rare bilateralpresentation has been described [52]. These polypsshow a mesenchymal fibrovascular core, often withadipose tissue and skeletal muscle fibres and are coveredin regular skin with hair appendages. In tonsillar hairypolyps, submucosal plates of elastic cartilage of uniformthickness resembling the external ear auricular tags andauricular cartilage have been reported [78]. Hairy polypsof the tonsils have been postulated to arise from thesecond pharyngeal pouch [17], but due to the presenceof the cartilage plates they have also been interpreted asaccessory auricles with a postulated origin from the firstpharyngeal arch [78].6.3.3 TonsillitisThe lymphoid tissues of Waldeyer’s ring play a key rolein initiating immune responses against inhaled andingested pathogens. The tonsils are responsible for therecognition and processing of antigens presented to thepharynx. The size of the tonsils is directly proportionalto the amount of lymphoid tissue, which increases duringantigen challenge. The reactive lymphoid hyperplasiaof the palatine tonsils is often simply referred to as“tonsillitis” and in the case of the pharyngeal tonsil as“(hyperplastic) adenoids”. Tonsillar hypertrophy is associatedwith normal childhood development, mostlydue to viral challenge or can be secondary to specificbacterial or viral infections. Childhood hypertrophy ofthe pharyngeal tonsil begins at approximately 2 years ofage or during infancy and usually regresses by 8 years ofage. Palatine tonsils hypertrophy at the end of the firstdecade, somewhat later than the pharyngeal tonsil. Theyregress by puberty and are atrophied in adults. The lingualtonsil enlarges at the time of puberty and regressesvery little during adult life [41]. Tonsillar hypertrophyis usually symmetrical and diffuse, but can be papillaryand unilateral.The normal flora of the naso- and oropharynx includesanaerobic bacteria such as gram-positive Actinomycesand Proprionibacterium, and gram-negativebacteria such as Bacteroides, Fusobacterium and Vibrio[202]. Actinomyces israelii is a common nosocomialsaprophyte in the oro-/nasopharyngeal cavity. The trueincidence of tonsillar manifestations of actinomyces isunknown, but has been reported to be as high as 40%[57, 120]. Occasionally, actinomyces form small sulphurgranules that can be seen as small yellow dots on thetonsillar surface. Larger aggregates of actinomyces mayproduce a tumour-like mass [172]. The tangled massesof gram-positive branching mycelial-like bacteria liewithin the crypts or are attached to the surface epitheliumof normal tonsils. Tonsillectomies for hypertrophiedtonsils or adenoids are one of the most common surgicalprocedures, but the term “tonsillitis” is still poorlydefined. Surgical resection specimens may demonstrateonly hyperplastic lymphoid tissue and lymph follicleswith enlarged germinal centres or no pathology atall [91].6.3.3.1 Bacterial TonsillitisBacterial suppurative tonsillitis is among the most frequentpaediatric infections. Group A beta-haemolyticstreptococci are the most frequent cause. Other commonisolates in bacterial tonsillitis are Hemophilus influenza,Streptococcus pyogenes, Streptococcus milleri and Staphylococcusaureus [97, 202, 205]. Children with acute streptococcaltonsillitis are significantly older than childrenwith viral tonsillitis. The treatment of choice is penicillinadministration for 10 days. Prevention of acute rheumaticfever is the principal goal of treatment. Surgicalspecimens of acute tonsillitis are rarely encountered. Thesurface epithelium may be ulcerated, and the surface andcrypt epithelium is infiltrated by neutrophilic granulocytesproducing a cryptitis with crypt abscesses. Acutebacterial infections may advance to intraparenchymaland peritonsillar abscesses (quinsy) with a lateral extensioninto the parapharyngeal space, base of skull and thesheath of the carotid artery [33, 64]. Rare other bacteria