Pathology of the Head and Neck

302 M.R. Canninga-Van Dijk10tomas have been described [63]. Choroidal osteomas candevelop within a degenerated choroidal haemangioma oran inflammatory scar, but can also be idiopathic.10.4.5.7 Metastatic TumoursMetastatic tumours to the eye have a predilection forthe highly vascular choroid. The metastases can be discoveredin a patient known to have a malignancy, butthey can also be the first presentation of the malignantdisease. Histology most often shows an adenocarcinomaand the primary tumour is found in the breast or lung[86]. More rare are metastases from thyroid carcinoma,carcinoid tumours, endometrial carcinoma, haemangiosarcomaand adenocarcinoma of the intestinal tract.The lesions usually show severe necrosis due to palliativeradiotherapy.10.5 Optic Nerve10.5.1 PapilloedemaAny condition in which the intracranial pressure israised can cause papilloedema. The prelaminar part ofthe optic disc is swollen and the peripapillary photoreceptorsare placed laterally. If the reason for the papilloedemais not identified, the oedema can present as atumour. This so-called pseudotumour cerebri is treatedby optic nerve fenestration to relieve the pressure in thesubarachnoid space. The pathologist will receive themeninges surrounding the optic nerve, which are histologicallycompletely normal.10.5.2 Optic NeuritisOptic neuritis presents as acute, unilateral and painfulvision loss. It can result from inflammatory disorders,can occur as isolated inflammation, or may be part ofthe spectrum of multiple sclerosis. Magnetic resonanceimaging is indicated to rule out compressive optic neuropathy.Spontaneous outcome of optic neuropathiesis favourable. Secondary inflammatory optic neuritis(infection, vasculitis, sarcoidosis) is rare and usuallypresents with atypical evolution or other symptoms.Histologically, the optic nerve in multiple sclerosis willshow a perivascular lymphocytic infiltrate with focalareas of demyelination and axonal atrophy at the endstage.10.5.3 Optic AtrophyIn a normal optic disc, a large bulge of nerve fibre isformed. In enucleated glaucomatous eyes, the optic discis obviously cupped and shrinks down to the laminacribrosa, which becomes bowed posteriorly. Reactive fibrovasculartissue fills the cupped disc.10.5.4 Tumours10.5.4.1 GliomaICD-O:9380/3Most glial tumours of the optic nerve are of the juveniletype. They present with slowly progressive proptosis.The juvenile tumours have a good prognosis,unlike the more rare adult types, which are invariablylethal. Bilateral optic nerve gliomas can be found inpatients with neurofibromatosis. Histologically, thejuvenile tumours are of the pilocytic type, while theadult tumours resemble the high-grade glioblastomamultiforme.10.5.4.2 MeningiomaICD-O:9530/0Meningiomas surrounding the optic nerve can resultfrom a primary tumour arising in the meningeal sheetof the optic nerve or can result from an intracranialmeningioma spreading into the orbit. As in the intracranialcompartment, meningiomas of the orbit occurmost commonly in middle-aged females. The tumourspresent with proptosis. Optic nerve sheath meningiomasin the adult group grow slowly and have a goodprognosis. Meningiomas at other sites in the head andneck are mentioned in Chaps. 2, 6 and 8.10.6 Lacrimal Glandand Lacrimal Passages10.6.1 Inflammatory ProcessesEnlargement of the lacrimal gland is often caused bychronic inflammatory processes that can have manydifferent causes. When chronic dacryoadenitis is associatedwith enlargement of the salivary glands, it iscalled Mikulicz syndrome. Mikulicz syndrome can becaused by many different diseases like sarcoidosis, tu-