salivary gland diseases 1
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Salivary Gland Diseases
BY
Dr, Ibrahim H. Ahmed .
( M. D. ) Otorhinolaryngology .
بسم هللا الرحمن الرحيم
الرحمن علم القرءان خلق اإلنسان علمه البيان »
{ 5: 1: الرحمن } . « الشمس والقمر بحسبان
نا واجعلنا مسلمين سلمة لك رب ة م تنا أم ي حيم ﴿ وأرنا مناسكنا وتب علينا لك ومن ذر اب الر و ك أنت الت ﴾١٢٨ إن
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 .
For communication
Dr, Ibrahim Habib Barakat .
M.D. ( Otorhinolaryngology )
E mail , salamatuall@yahoo.com.
salamatuall@hotmail.com .
www.facebook.com/Dr.Ibrahim.Barakat
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