Warthin's tumour

Warthin's Tumour

· Arises in the parotid gland

· Tall,eosinophilic columnar cells which form a much folded layer covering dense lymphoid tissue,includng many germinal centres

· These structures line and form papillary projections into cystic spaces

Pleomorphic adenoma

Pleomorphic adenoma

· Account for about 75% of parotid tumors

· Arise mainly from duct epithelum or myoepithelial cells

Important histological features

· Capsule never complete

· Ducts

· Sheets or stands of dark staining epithelial cells

· Squamous metaplasia and focci of keratin

· Fibrous and elastic tissue

· Myxoid tissue

· Cartilage,sometimes calcified,rarelytrue bone formation.

· The fibroid,myxoid,or cartilagenous,mesenchymal elements are due to the pluripotential properties of myoepithilial cells.

Causes of Xerostomia

Organic cauases

· Sjogrens syndrome

· Irradiation

· Mumps

· HIV infection

· HCV infection

· Sarcoidosis

· Amyloid

· Iron deposition(haemochromatosis,thalassaemia)

Funtional causes

· Dehydration

· Fluid deprivation or loss

· Haemorrhage

· Persistent diarrhoea and or vomiting

· Psycogenic(anxiety states,depression)

· Drugs

Drugs

· Diuretic overdose

· Drugs with antimuscarinic effect

Atropine,ipratropium,hyoscine and other analogues

Tricyclic and some other antidipressants

Antiemetics(including anti histamines and phenothiazenes)

Neuroleptic,particularly phenothiazenes

· Some older antihypertensives(ganglion blockers and clonidine)

· Drugs with sympathomimetic actions

'cold cures' containingg ephidrine,etc.

Decongestants

Bronchodilators

Appetite supressants particularly amphetamines

Mucous extravasaton cyst and Mucous retention cyst

Mucous extravasation cyst(Mucoceles)

· Affect the minor salivary glands,particularly of the lip

· Often form in lower lip,sometimes in floor of the mouth(Ranula)

· They are obviously cystic,hemispherical,fluctuant and bluish.

· Saliva leaking from the damagedducts into the superficial surrounding tissues excitesand inflammatory reaction

· The pools of saliva gradually coalese to form a rounded collection of fluid surrounded by compressed connective tissue without epithelium

Mucous retention cyst

· Mucocele cannot be distinguished from a retention cyst clinically.

· Remnants of the minor mucous salivary glands are visible together with their dilated ducts,the epithelium of which is the epithelial lining of the cyst.

Necrotizing sialometaplasia

Necrotizing Sialometaplasia

A rare condition in which there is ulceration usually in a smoker in the palate,which heals spontaneously over several weeks.Association with salivary gland infractions.histology can be confusing,since it has been appearance resembling neoplasia(Pseudo epitheliomatous hyperplasia)

· Affects mainly minor glands of the palate

· Painless,ulcerated swelling,the margins are irregular and heaped up or everted.

· Chronic inflammation in the minor salivary glands and necrosis of acini

· Duct tissues undergoes squamous metaplasia and proliferates to produce a pseudomembranous appearance