Pathology of the Head and Neck

Ear and Temporal Bone Chapter 8 239deep to which the connective tissue is chronically inflamed.There is often elastic cartilage in the deep wallof the sinus. Branchial cleft cysts are more extensivelydiscussed in Chap. 9.8.2.3 Tumour-Like Lesions8.2.3.1 ChondrodermatitisNodularis HelicisIn chondrodermatitis nodularis chronica helicis, sometimesknown as Winkler’s disease, a small nodule formson the auricle, usually in the superior portion of the helix.Pain is always a prominent feature.Histological examination of biopsies of such lesionsin which the elastic cartilage underlying the skin of theauricle is particularly well-represented, shows ulcerationof the skin of the auricle and complete necrosis of the tipof the underlying elastic cartilage of the auricle. In somecases a piece of extruded necrotic cartilage may be seenon the floor of the ulcer. The perichondrium of the elasticcartilage in this region shows obstructive thickeningof small arteries.The helix is one of the furthest points from the sourceof the arterial blood supply of the pinna. It seems likelythat obstruction of small arteries of the perichondriumis the primary lesion leading to cartilage necrosis,and that the acute inflammation and epidermal ulcerationare secondary to the nearby cartilage necrosis. Anassociation between chondrodermatitis nodularis helicisand systemic sclerosis has been described [12]. In thiscondition obstructive changes are frequently found insmall arteries.8.2.3.2 Keratosis Obturansand Cholesteatomaof External CanalIn keratosis obturans the keratin produced by exfoliationfrom the skin of the tympanic membrane and externalcanal is retained on the epithelial surface and forms asolid plug. This enlarges and may cause circumferentialerosion of the bony canal. Keratosis obturans is probablythe result of a defect of the normal migratory propertiesof the squamous epithelium of tympanic membraneand adjacent ear canal that causes the accumulation ofkeratinous debris [20]. A minor degree of this process –keratosis of the tympanic membrane – in which depositsof keratin grow on the eardrum and cause tinnitus hasalso been found to be associated with absent or defectiveauditory epithelial migration [103].A condition that has been distinguished from keratosisobturans is cholesteatoma of the external canal. Inthis lesion epidermoid tissue appears to penetrate intothe wall of the deep external canal causing localised osteonecrosisand bone erosion [87].8.2.3.3 Keratin GranulomaA granulomatous process may result in the external earcanal when keratin squames become implanted into thedeeper tissues following traumatic laceration [39]. Thegranuloma contains foreign body-type giant cells, histiocytes,lymphocytes, plasma cells and flakes of keratin.The latter are strongly eosinophilic and birefringentin polarised light. Aural polyps frequently contain suchgranulomas, but the keratin is then more likely to be derivedfrom a middle ear cholesteatoma (see below).8.2.3.4 Angiolymphoid Hyperplasiawith Eosinophiliaand Kimura’s DiseaseSynonyms for angiolymphoid hyperplasia with eosinophiliaare epithelioid haemangioma, benign angiomatousnodules of face and scalp, atypical pyogenic granuloma,and several other terms. Although this entity wasfirst described by Kimura, “Kimura’s disease” is nowbelieved to be a different condition (see below).Angiolymphoid hyperplasia with eosinophilia mayoccur anywhere in the skin, especially on the scalp andface, but there is a particular predilection for the externalauricle and external auditory meatus. It is a lesion ofyoung and middle-aged of both sexes and all races.Grossly, there are sessile or plaque-like red or reddish-bluelesions from 2 to 10 mm in diameter, whichmay coalesce to form large plaques that obstruct the earcanal. On transection the lesion is seen to be presentin the dermis and subcutaneous tissue. Microscopically,there is a mixture of two proliferated elements in thedermis: blood vessels and lymphoid tissue. The bloodvessels are mainly capillaries lined by plump, often protruding(hobnailed) sometimes multilayered, endothelialcells (Fig. 8.3). Occasionally an artery or vein showingintimal fibrous thickening is part of the vascular component.Solid clusters of cells, which are often vacuolated,show features intermediate between endothelial cellsand histiocytes are also observed [6]. The lymphoid tissuemay possess germinal centres. Eosinophils (oftenextremely numerous), mast cells and macrophages mayalso be prominent.Kimura’s disease is commoner in orientals, mainlyaffecting young males. It is a chronic inflammatory conditionof unknown aetiology. It presents as large, deepand often disfiguring, subcutaneous masses in the preauricular,parotid and submandibular regions. Often,there is enlargement of regional lymph nodes. Occasion-