Pathology of the Head and Neck

Nasopharynx and Waldeyer’s Ring Chapter 6 177abcdefFig. 6.3. Nasopharyngeal angiofibroma. a–b Nasopharyngeal angiofibromasare large, white, firm, bulging tumours covered by respiratorymucosa. c–d Abnormal large muscular and smaller sinusoidalvessels are embedded in a fibrous and partly sclerotic stroma.The muscular vessels exhibit irregular muscle walls with varyingthickness and arbitrary arrangement of the individual smoothmuscle cells. e–f The stroma is either fibrous or myxoid with stellateor spindled cellsFig. 6.2. Salivary gland anlage tumour. a–c Salivary gland anlagetumours have an intact surface epithelium, which may be partlykeratinized. The branching epithelial proliferations show ductsfilled with proteinaceous casts. The stroma is myxoid and containsnumerous plasma cells and lymphocytes. d–e There are solidsquamous areas with keratin-filled cysts and calcifications. f–gOther areas are dominated by proliferations of spindle cells in solid,fascicular and nested arrangement with occasional ductal andcystic elements. Haemorrhage is common