Retention phenomenon

1. MUCOCELE AND RENULA
Dr Amitha

2. The mucocele is a common lesion of the oral mucosa involving salivary glands
and their ducts.
They result from
 Traumatic severance of a salivary duct
 Produced by biting the lips or cheek
 Pinching the lip by extraction forceps and the like, leading to spillage of
mucin into the sorrounding tissues.
Such trauma has been implicated in the formation of mucoceles.
There is no known history of trauma in many cases.
cyst lack epithelial lining they are not true cyst.
MUCOCELE

4. Mucoceles are commonly observed in all decades of life,
with increased predilection in children and young adults,
possibly because of the higher chance of trauma in latter
age group.
Clinically it appears as a raised , domeshaped
vesicles,ranging in size from 1 to 2 mm to several
centimetres.
There might be a history of rupture, collapse, and refilling
which may be repeated.
The mucoceles may lie deep in the tissues or exceptionally
superficial and thus depending upon the location it present

5. ETIOLOGY AND PATHOGENESIS
The mucous retention phenomenon is a common lesion although only
few studies have been reported.
Many authorities formerly believed that this type of lesion resulted from
1.obstruction of the duct of a minor salivary gland, but experimental
investigations on mice by Bhaskar and his associates and rats by
Standiush and Shafer failed to produce mucous retention phenomenonby
ligation of the submaxillary and sublingual gland ducts.
2. The studies of Bhaskar demonstrated instead that if the salivary duct
was severed so that a continuous pooling of of saliva occured in the

6. These investigations appear to indicate that traumatic severance of a
salivary duct, such as that produced by biting of the lipss or cheek or
pinching the lip by extraction forceps, preecedes the development of the
retention phenomenon.
It is also possible that chronic partial obstruction of the salivary duct ,
partial obstruction could result from a small piece of intraductal calculus
may be the etiologic importance.
Occasional cases of calculus in the ducts of accesory salivary glands or
sialolithiasis have also been reported.
Thus mucocele often have been classifiedas
1.an extra vassaation mucocele

7. HISTOLOGIC FEATURES
Mucoceles consist of a cicumscibed cavity in the
connective tissue and submucosa producing an
obvious elevation of the mucosa with thinning of the
epithelium as though it were stretched.
The wall of the cavity is made up of lining of
compressed fibrous connective tissue and fibroblasts.

8. The connective tissue wall is essentially granulation
tissue but in any event it usually shows infiltration by
abundant number of polymorphonuclear leukocytes,
lymphocytes and plasma cells

9. The lumen of the cyst like cavity is filled with the spilled mucin containing
variable numbers of cells,chiefly leukocytes and foamy
histiocyes(macrophages).
Occasional mucoceles demonstrate an intact flattened epithelial lining. It
is probable that this simply represents the portion of the excreatory duct
bordering the line of severance, if severance is actually the manner in
which these lesion develop.
The flattened epithelial lining has been reffered to as epithelium of the
“feeder duct” in other instances the epithelium lined mucocele represents
a mucous retention cyst.

10. TREATMENT
Treatment of the mucous retention phenomenon is excission.
If the lesion is simply incised, its contents will be evacuated but rapidly
filled as soon as healed.
There is occasional recurrence after excision, but this possibility is less
likely if the associated salivary gland acini are removed also.
The excised tissue should be given for microscopic examination to rule out
the possibility of a salivary gland tumor.

11. RANULA
The ranula is a form of mucocele which specifically occurs in the floor of
the mouth in association with the ducts of the submaxillary and
sublingual gland.
The etiology and pathogenesis appered to be same as the retention cyst.
Some authors believed that it may arise through duct blockage or through
the devepment of the ductal aneurysm.

12. CLINICAL FEATURES
The lesion which is rare compared to the usual mucocele, develops as a slow
enlarging painless mass on side of the floor of the mouth . Since the lesion is
usually deep seated one, the overlying mucosa is normal in appearance.
If the lesion is superficial the mucosa may have a translucent bluish color.

13. HISTOLOGIC FEATURES
The microscopic features are simillar that of smaller mucocele except that
a definite epithelial lining is sometimes present.
Because of this lining most investigators consider raula as a true retention
cyst.

14. PATHOPHYSIOLOGY
The development of mucoceles and ranulas depend on the disruption of the
flow of saliva from the secretory apparatus of the salivary glands.The
lesions are most often associated with mucus extravasation into the
adjacent soft tissue caused by a traumatic ductal insult;the insults include a
crush type injury and severance of the excreatory duct of the minor salivary
gland.
The disruption of the secretory glands results in extravassation of the
mucous from the gland into the sorrounding soft tissue

15. The rupture of an acinar structure caused by hypertension from the ductal
obstruction is another possible mechanism for the development of such
lesion.
Furthermore, trauma that results in damage to the glandular parenchymal
cells in the salivary gland lobules is another potential mechanism.
Regarding superficial mucoceles,trauma does not always appear to play
important role in the pathogenesis.

16. Thankyou
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Dr Amitha