Salivary Gland Diseases

BY

Dr, Ibrahim H. Ahmed .

( M. D. ) Otorhinolaryngology .

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ANATOMY

Major salivary glands

Paired

parotid ,

Submandibular ,

Sublingual .

Minor salivary glands

Palate ,

nasal cavity ,

oral cavity .

Embryology

The major salivary glands develop from the 6th-8th weeks of gestation as outpouchings of oral ectoderm into the surrounding mesenchyme. The parotid enlage develops first, the fully developed parotid surrounds CN VII. Parotid gland develops in its unique anatomy with entrapment of lymphatics in the parenchyma of the gland. Furthermore, salivary epithelial cells are often included within these lymph nodes. The minor salivary glands arise from oral ectoderm and nasopharyngeal endoderm. They develop after the major salivary glands. During development of the glands, autonomic nervous system involvement is crucial; sympathetic nerve stimulation leads to acinar differentiation while parasympathetic stimulation is needed for overall glandular growth.

Major salivary glands

Parotid gland

The parotid gland overlies the angle of the mandible .

Superiorly is related to zygoma .

Posteriorlly is related to cartilage of ear canal .

Medially is related to parapharyngal space

Facial nerve & parotid gland

The facial n. exits the stylomastoid foramen and runs through the substance of the parotid gland , splitting into its 5 main branches.

The plain of facial nerve is used to divide the gland into “ superfacial “ and “ deep “ lobes .

Branches of facial n. within parotid gland

2 divisions: 1) Temperofacial (upper) 2) Cervicofacial (lower)

5 terminal branches: 1) Temporal 2) Zygomatic 3) Buccal 4) Marginal Mandibular 5) Cervical

3

The surgical landmarks of CN VII intraoperatively : 1) Tragal pointer – points to the main trunk of CN VII proximal to the Pes and 1-1.5 cm deep and inferior to the pointer .2) Tympanomastoid suture – traced medially, the main trunk of VII is encountered 6-8 mm deep to the suture line . 3) Posterior belly of Digastric muscle – is a guide to the Stylomastoid foramen; the trunk of VII is just superior and posterior to the cephalic margin of the muscle . 4) Styloid process – sits 5-8 mm deep to the Tympanomastoid suture; the trunk of VII lies on the posterolateral aspect of the Styloid near its base .

The Auriculotemporal nerve :

The Auriculotemporal nerve , a branch of V-3, runs anterior to the EAM, paralleling the superficial temporal artery and vein. This nerve carries Parasympathetic postganglionic fibers from the otic ganglion to the Parotid gland. Thus, when this nerve is injuredintraoperatively, aberrant parasympathetic innervation to the skin results in Frey’s Syndrome (i.e., gustatory sweating). This nerve may be resected intentionally to avoid Frey’s Syndrome. In addition, the Auriculotemporal nerve provides sensory innervation to the parotid capsule, and the skin of the auricle and temporal region. As a result, referred pain from parotitis can involve the auricle, EAM, TMJ, and temples.

Parotid duct

Stensen’s duct (parotid duct) arises from the anterior border of the Parotid and runs superficial to the masseter muscle, then turns medially 90 degrees to pierce the Buccinator muscle at the level of the second maxillary molar where it opens onto the oral cavity. The buccal branch of CN VII runs with the parotid duct. The duct measures 4-6 cm in length and 5 mm in diameter.

Parotid Gland

Submandibular gland

Superolaterally , the submandibular gland abuts the body of the mandible

Medially the lingual and hypoglossal nerves,

Anteriorly , the mylohyoid muscle .

Posteriorly , the tail of parotid gland .

Lateraly , marginal branch of facial n.

The Submandibular duct (Wharton’s duct) :

Wharton’s duct exits the medial surface of the gland and runs between the Mylohyoid (lateral) and Hyoglossus muscles and on to the Genioglossus muscle.Wharton’s duct empties into the intraoral cavity lateral to the lingual frenulum on the anterior floor of mouth. The length of the duct averages 5 cm. The Lingual nerve wraps around Wharton’s duct, starting lateral and ending medial to the duct, while CN XII parallels the Submandibular duct, running just inferior to it.

The identification of CN XII, the Lingual nerve, and Wharton’s duct is absolutely essential prior to resection of the gland.

Submandibular Gland

Sublingual Gland This gland lies just deep to the floor of mouth mucosa between the mandible and Genioglossus muscle. It is bounded inferiorly by the Mylohyoid muscle.

Wharton’s duct and the Lingual nerve pass between the Sublingual gland and Genioglossus muscle.

The Sublingual gland has no true fascial capsule.

The Sublingual gland is drained by approximately 10 small ducts (the Ducts of Rivinus), which exit the superior aspect of the gland and open along the Sublingual fold on the floor of mouth.

Occasionally, several of the more anterior ducts may join to form a common duct (Bartholin’s duct), which typically empties into Wharton’s duct.

Sublingual Gland

Minor Salivary Glands

The minor salivary glands lack a branching network of draining ducts. Instead, each salivary unit has its own simple duct.

The minor salivary glands are concentrated in the Buccal, Labial, Palatal, and Lingual regions. In addition, minor salivary glands may be found at the superior pole of the tonsils (Weber’s glands), the tonsillar pillars, the base of tongue (von Ebner’s glands), paranasal sinuses, larynx, trachea, and bronchi.

The most common tumor sites derived from the minor salivary glands are the palate, upper lip, and cheek.

Microanatomy of the Salivary Glands The secretory unit (salivary unit) consists of the acinus, myoepithelial cells, the intercalated duct, the striated duct, and the excretory duct.All salivary acinar cells contain secretory granules; in serous glands, these granules contain amylase, and in mucous glands, these granules contain mucinMyoepithelial cells send numerous processes around the acini and proximal ductal system (intercalated duct), moving secretions toward the excretory duct. The lumen of the acinus is continuous with the ductal system, made up of (from proximal to distal) the intercalated duct, the striated duct, and the excretory duct. The intercalated duct is lined by low cuboidal epithelial cells. The striated duct is lined by simple cuboidal epithelial cells proximallyExcretory ducts are lined by simple cuboidal epithelium proximally and stratified cuboidal or pseudostratified columnar epithelium distally.

Serous acini & mucous tubules

The sublingual glands are another tubuloacinar gland, but in this case mucous cells predominate. Acini are composed of both serous and mucous cells with the serous cells mostly displaced to the terminal portion of the acini as outpocketings. They appear as darkly staining crescents of cells (serous demilunes) around the ends of mucous tubules

Function of Saliva

1) Moistens oral mucosa.

2) Moistens dry food and cools hot food.

3) Provides a medium for dissolved foods to stimulate the taste buds.

4) Buffers oral cavity contents. Saliva has a high concentration of bicarbonate ions.

5) Digestion. Alpha-amylase, contained in saliva, breaks 1-4 glycoside bonds, while lingual lipase helps break down fats.

6) Controls bacterial flora of the oral cavity.

7) Mineralization of new teeth and repair of precarious enamel lesions. Saliva is high in calcium and phosphate.

8) Protects the teeth by forming a “Protective Pellicle”. This signifies a saliva protein coat on the teeth which contains antibacterial compounds. Thus, problems with the salivary glands generally result in rampant dental caries.

Pseudoparotomegaly

1- Hypertrophy of the masseter ( young women ).

2- Aging ( absorption of adipose tissue & salivary glands become more obvious ) .

3- Dental causes ( dental infection spreads to lymph nodes

within parotid or submandibular ) .

4- Tumors in parapharyngeal space

- Chemodectoma .

- Glomus vagal tumors .

- Schwanoma of vagus .

- Schwanoma of sympathetic trunk .

- Enlarged lymph nodes .

- T . B .

- Metastatic.

Tumour → displace parotid or

submandibular gland .

5- Tumors of Infratemporal fossa

- Haemangioma .

- Haemangiosarcoma .

- Leimyosarcoma .

- Hydatid cyst .

- Liposarcoma .

- Metastatic lymph node(s) .

- Tumour extend through mandibular notch or under zygomatic arch .

6- Mandibular tumors

osteosarcoma

chondrosarcoma

- ramus , mimic

parotid enlargement.

- body, mimic submandibular enlargement

7- mastoiditis

Mastoiditis → subperiosteal abscess → dains into →sternomastoid muscle or digastric muscle → lifting tail of parotid .

8- Intraparotid lesions

- facial n. neuroma .

- temporal a. aneurysms .

- enlarged lymph nodes : infection , metastatic .

- parotid cycts .

Metabolic Parotomegaly

- gout .

- Cushing's disease .

- myxedema .

- D . M .

Non Neoplastic Salivary Gland Disorders

- Sialectasis .

- Sjogren syndrome .

- Salivary gland cysts .

- Salivary fistulae .

• Reactive conditions• mucoceles and ranulas• irradiation reactions• sialolithiasis• necrotizing . . .sialometaplasia• Infectious• Nutrition disorders• Medication reactions• Immunologic disorders

Mucoceles of salivary glands

Mucoceles

- Most common reactive condition of

the minor salivary glands

- Mucoceles form when trauma to

excretory ducts of the minor glands

allows the spillage of mucus into the

surrounding connective tissue

- formation of painless, smooth surfaced,

bluish lesions

mucoceles

The lower lip is the most frequent site followed by the buccal mucosa , the ventral surface of the tongue, the floor of the mouth, and the retromolar region .

Treatment:• observation• surgical excision .

Ranulas

Ranulas

- The result of blocked sublingual gland

. ducts

- Ranulas are unilateral, soft-tissue lesions,

often with a bluish appearance.

- They vary in size and may cross the

midline of the mouth and cause deviation

of the tongue

- A mucosal extravasation that herniates

the mylohyoid muscle is called a

"plunging" ranula

Treatment of ranula

Treatment of a Ranula

Surgical excision of the involved gland

and marsupialization

Marsupialization: suturing its walls to

an adjacent structure, leaving the

packed cavity to close by granulation

Irradiation Reaction

- A common side effect of tumoricidal

doses of ionizing radiation is xerostomia

- Frequent sips of water and frequent mouth

care are the most effective interventions

for xerostomia

- Saliva substitutes (e.g., mixed solutions of

methylcellulose, glycerin, and saline) or

pilocarpine hydrochloride may help these

symptoms

Sialectasis

Pathogenesis : -

The epithelial debris within salivary gland lead to formation of a stone which blockades the salivary gland duct , causing swell up of the gland & if persists for some days , infection & abscess formation will occur .

- History : - painful swelling of the gland during meal .- Examination : -

1- Submandibular gland ;stone in the duct can be palpated or seen .2- parotid gland :

the mout of the duct is oedamatous & pouting .

Drainage of saliva from the duct can be seen when massage the gland .

Sialectasis - Clinical picture

Sialectasis - Investigations

1- Plain radiograph : radio opaque stone .

2- Sialogram : normal .

Overfilled

Obstruced duct

Sialectasis ; cystic , globular or saccular

Plain radiograph shows radio opaque stone

salivary stones

80 % occur in the submandibular gland

10 % occur in the parotid gland

7 % occur in the sublingual gland

80 % of submandibular stones are radio opaque

Most parotid stones are radiolucent

Stone in Wharton’s duct

If partial obstruction occurs swelling may be mild with chronic painful enlargement of the gland

If diagnostic doubt then stone can be demonstrated by sialogram

Sialectasis- treatment

1- No treatment .

2- Peroral removal of a calculus .

3- Marsupialization of the duct .

4- Ligation of duct ( dismissed ) .

5- Duct dilatation ( dismissed ) .

6- Tympanic neurectomy .

7- Removal of submandibular gland .

8- Total parotidectomy .

Treatment is by either removal of stone from duct or excision of the gland

Necrotizing Sialometaplasia

-- Usually involves minor salivary glands

-- Occurs secondary to vascular infarct due to

• smoking, trauma, DM, vascular disease,

- Age range 23-66 yrs

- 1-4 cm ulceration

- resembles mucoepidermoid carcinoma

and SCCA clinically and histologically

- Usually heal in 6-10 weeks-

Nutrition Disorders

Nutrition disorders such as pellagra (ie,

niacin deficiency), kwashiorkor (ie, protein

deficiency), beriberi (i.e, thiamine

deficiency), and vitamin A deficiency are

associated with parotid gland enlargement

Malabsorption syndromes (e.g., parasitic

and protozoan infections, amebic

dysentery, celiac sprue) also can cause

malnutrition and result in salivary gland dysfunction

Obesity & parotid ( excessive ingestion of starch ) .

Medication Reactions

Many medications

(e.g., amitriptyline ,Imipramine , nortriptyline ,atropine,dextropropoxyphene,phenothiazinederivatives , ↑ oestrogen oral contraceptive pills , antihistamines) decrease salivary flow and cause

parotid enlargement .

Metabolic Conditions

Patients with alcoholic cirrhosis often

experience asymptomatic enlargements of

their parotid glands, which are attributed

to chronic protein deficiency

Diabetes mellitus and hyperlipidemia

cause fatty infiltrations that replace the

functional parenchyma of the salivary

glands and decrease the flow of saliva

Parotitis

Pathgenesis :

Acute :- viral , bacterial , fungal .

Chronic :- T. B.

- sarcoid .

- actinomycosis .

- leprosy .

- tularaemia .

Parotitis

- clinical picture & diagnosis :-

• 1- severe pain made worse by eating .

• 2- high temperature .

• 3- acute worsening of pain if patient sips a little lemon juice .

Parotitis - investigations

- Lab. Investigations :

WBC , E.S.R., viral titers , bacteriology .

- Radiological investigations :

1- plain radiographs .

2- sialography .

3- scanning .

Parotitis - treatment

- conservative :

1- oral hygiene .

2- analgesic .

3- antibiotic .

- Surgical treatment :

1- drain abscess .

2- peroral stone removal of duct .

Immunologic conditions

HIV may manifest with parotid gland

enlargement and parotid

lymphadenopathy often are observed in

these immunocompromised patients.

Parotid gland enlargement may be caused

by benign lymphoepithelial lesions in the

gland, hypertrophied periparotid lymph

nodes, or secondary infections from CMV

Sjogren ‘s Syndrome

_ Clssification : -

1- Primary Sjogren Syndrome : xerostomia , xerophthalmia .

2- Secondary Sjogren syndrome : xerostomia , xerophthalmia , c. t. disease .

3- Benin lymphoepithelial lesion ( parotid gland ) .

4- Aggressive lymphocytic behaviour ( parotid gland )

Sjogren ‘s Syndrome

- Clinical picture : -1- EYE : redness , itching , photosensetivity , inability to

tolerate contact lenses .

2- Ear : S . O . M .

3- Nose : N. crustation , epistaxis .

4- Mouth : glazing oral mucosa .

5- Nasopharynx : sticky secretion .

6- Salivary gland : enlargement .

7- Larynx : laryngitis sicca .

Sjogren ‘s Syndrome

8- G. I. T. : disorder of oesophagus motility .Achlorhydria .1ry biliary cirrhosis .Ch. Hepatitis .

9- Endocrine : thyroiditis , pancreatitis .

10- blood ; cryglobulinaemia , hypergammaglobulinaemic purpra .

11- Vascular : vasculitis .

12- Others : polyarthritis , chronic graft versus host disease .

xerophthalmia

Primary Sjogren Syndrome : xerostomia , xerophthalmia .

salivary gland enlargement 30%) )

Sjogren ‘s Syndrome

- Investigation : -

1- Blood : ↑↑ E.S.R., ↑↑ all Ig. Esp. IgG , + RH factor , + A.N.A.

2- Specific immunological test : SSA & SSB antigens .

3- Schirmer’s test : < 5 mm in 5 mins → xerophalmia .

4- Examination of eye with Rose Bengal dye → keratoconjunctivitis .

Sjogren ‘s Syndrome

5- Salivary flow rate : < 0.5 ml / min. → xerostomia .

6- Labial biopsy :

Grade 1 : slight lymphocytic infilteration .

Grade 2 : < 50 lymphocyte / mm

Grade 3 : 50 lymphocyte / mm

Grade 4 : > 50 lymphocyte / mm

6- Radiology : sialography → normal or abnormal leakage of lipiodol into stroma of the gland .

labial or minor salivary gland biopsy

Axial FSEIR: Enlarged bilateral parotid glands with hypointense cystic-like changes .

Axial T2W FSE: enlarged parotid glands containing T2 hyperintense globular collections of watery saliva

Sjogren ‘s Syndrome

Treatment : -

- steroids .

- immunosuppressive drugs .

- artificial tears , synthetic saliva .

- bromhexin 40 mg / day .

Follow up : lymphoma .

Salivary fistulae

- origin : - parotid .

- submandibular .

- Causes : - - surgery , facial trauma , sepsis .

- Treatment : -

1- prevention .

2- reduction of salivary production .

3- Excision of the fistulae .

4- Submandibular gland excision .

5- Parotidectomy .

Thank you

For communication

Dr, Ibrahim Habib Barakat .

M.D. ( Otorhinolaryngology )

E mail , salamatuall@yahoo.com.

salamatuall@hotmail.com .

www.facebook.com/Dr.Ibrahim.Barakat

Thank you