Pathology of the Head and Neck

Nasopharynx and Waldeyer’s Ring Chapter 6 187ical features in patients with advanced disease are effacementof nodal architecture, loss of the normal lymphoidcell population with replacement by benign plasma cellsand increased vascularity [53, 174, 197].Acute non-bacterial tonsillitis and hypertrophy canbe the first sign of a post-transplant lymphoproliferativedisorder [163]. In a study of 42 paediatric transplantpatients, 28% had involvement of Waldeyer’s ring [147].In immunosuppressed children in particular with rapidprogressive enlargement of the tonsils lymphoma shouldbe suspected [180].6.3.4 Benign Tumoursof Waldeyer’s Ring6.3.4.1 Squamous PapillomaICD-O:8121/0Squamous papillomas represent the majority of benigntonsillar and oropharyngeal tumours [89]. They arise onthe soft palate and uvula, but also on the posterior wallof the oropharynx. They have an exophytic appearance.The fibrovascular stalk is covered in a regular, stratified,non-keratinising or keratinising squamous mucosa,with occasional parakeratosis. The vast majorityshow no viral cell changes. Some papillomas, however,show HPV-related cell changes with the typical koilocyteswith small pyknotic nuclei and a perinuclear halo,the so-called tonsillar condylomata [190]. Subtyping forHPV demonstrates typically low-risk HPV 6 and 11. Fora detailed description of squamous papilloma in the oropharynxsee Chap. 1.6.3.4.2 LymphangiomatousTonsillar PolypLymphangiomatous tonsillar polyps are benign tumoursof the palatine tonsil, accounting for about 2%of all tonsillar neoplasms. They have been reportedby a number of different names such as angiomas,angiofibromas, fibrolipoma, polypoid tumour containingfibro-adipose tissue and hamartomatous tonsillarpolyp and lymphangiectatic fibrous polyp [105]. Theyare pedunculated, mostly unilateral proliferations inthe upper pole of the palatine tonsils in adults andchildren (age range of reported cases 3–63 years, witha median age of 26 years). Clinical symptoms are dysphagia,sore throat and the sensation of “a mass in thethroat”. Lymphangiomatous tonsillar polyps measurebetween 0.5 and 4 cm. They are covered by respiratoryepithelium or glycogenated or keratinised squamousepithelium with foci of hyper- and parakeratosis.Clusters of lymphocytes are found within thesquamous epithelium (lymphocytic epitheliotropism)or in the submucosa beneath the basement membrane(Fig. 6.7). The stalk consists of dense fibroustissue, adipose tissues or myxoid and oedematousstroma, which contains numerous small to mediumsized,endothelial-lined, lymphatic/vascular channelsfilled with proteinaceous fluid and lymphocytes[82]. Valves can be appreciated. Some endothelialcells stain with antibodies to factor VIII, CD31 andCD34; others are non reactive. The pathogenesis ofthe lymphangiomatous polyps is uncertain. They maybe a hamartomatous proliferation, but they may alsobe the result of a chronic inflammatory hyperplasia.Especially in children, lymphangiomatous polyps andpapillary lymphoid polyps may be a manifestation ofa chronic tonsillitis.6.3.5 Carcinomasof Waldeyer’s RingICD-O:8070/3Carcinomas of Waldeyer’s ring are typically squamouscell carcinomas (SCC) arising in the palatine tonsil andthe base of the tongue. They are more common in menthan in women and present during the 5th and 7th decades.Smoking, alcohol, poor hygiene, but also HPVinfections, are risk factors [32, 51, 160]. Some SCC maybe fungating and exophytic tumours, others present asdeeply ulcerated infiltrative lesions. The majority ofSCC of the palatine tonsil and base of the tongue typicallygrow undetected for some time as they arise fromthe crypt epithelium. At the time of clinical detection,extensive infiltration of the surrounding tissues andregional cervical lymph node metastases are typical.The metastases to cervical lymph nodes are often thepresenting symptom of tonsillar carcinomas (Fig. 6.8).Histologically, primary carcinomas of the palatinetonsil and base of the tongue can be divided into keratinisingand non-keratinising subtypes. The solidnon-keratinising carcinomas predominate. Tonsillarcarcinomas may show a “transitional type” differentiationresembling lymphoepithelial carcinoma and EBVpositivity [111, 132]. A basaloid-squamous carcinomaof Waldeyer’s ring has also been described [7, 159]. Thelymph node metastases can be quite large and are oftencystic with multilocular complex lumina and papillaryprojections [165, 166, 189]. The majority of cysticmetastases are lined with a stratified epithelium withcytological atypia and numerous mitoses. Foci of keratinisationcan be appreciated. The cysts mostly containnecrotic tumour cells and debris. A minority of thecystic lymph node metastases is filled with clear fluid.Fluid-filled cystic metastases are more common in carcinomasof the base of the tongue than those arisingfrom the palatine tonsils. It has been postulated that