MucocoelesBY Dr ABOUZR M.

ESHAQENT SUDAN

Definition

• A mucocoele is an epithelial-lined, mucus-containing sac completely filling the sinus and capable of expansion.

SITE

• The fronto-ethmoidal region is by far the most commonly affected overall and the maxillary sinus the least.

• Fronto-ethmoidal area is more susceptible to mucocoele formation due to the complexity of its drainage, as compared to the sphenoid and maxillary sinuses.

AETIOLOGY

• There may be a considerable time lag between the initiating factor and the clinical presentation with the mucocoele.

• In the case of surgery or trauma this is an average of 23 years, whereas following an acute infective episode the mean time to presentation is 22 months.

• Mucocoeles are thought to arise as a consequence of obstruction plus inflammation. Three main theories of pathogenesis are found in the literature:

1. pressure erosion.2. cystic degeneration of glandular tissue.3. active bone resorption and regeneration.

CLINICAL FEATURES

• Typically, patients with mucocoeles in the fronto-ethmoidal region are referred to ophthalmic surgeons in the first instance due to orbital displacement.

• Endoscopic examination may reveal the expanded mass presenting in the nasal cavity and acute infection, and/or attempts at drainage may result in fistulas through the upper lid.

• The mucocoeles in the maxillary sinus may expand into the nasal cavity producing nasal obstruction or erode the anterior wall producing swelling of the cheek. In addition the floor of the orbit may be lifted up, again resulting in displacement of the globe.

• In the sphenoid the intimate relation of the sinus to the orbital apex and cavernous sinus may lead to an acute presentation with visual disturbance, including diplopia and blindness.

• The patient may complain of headache which is typically referred to the occipitoparietal region.

IMAGING

• Computed tomography (CT) scanning is the optimum method of demonstrating a mucocoele,

differential diagnosis

• fungal disease;• cholesterol granuloma;• odontogenic cyst (maxilla);• neoplasia:- benign;- malignant.

TREATMENT

• In the majority of cases an endonasal endoscopic approach may be utilized.

• the advantages of the endoscopic approach are the lack of external scar, no disturbance of the trochlea and no supraorbital paresthesia.

• Although there will be significant reduction in the orbital displacement, a residuum of expanded bone may take some weeks or months to remodel.

• Patients should therefore be warned that the final cosmetic result may not be apparent for several months. However, this also has the advantage of minimizing any double vision secondary to the decompression.

• However, in a number of more complicated cases, particularly in the presence of significant pathology and/ or previous surgery, a combined endoscopic and external approach may be necessary in the frontal region.

• Whatever approach is used, there is absolutely no necessity to reconstruct areas of bone resorption even when there is wide spread dehiscence of the skull base.

COMPLICATIONS

• The complications of endoscopic surgery are minimal There is a potential risk of hemorrhage, a cerebrospinal fluid (CSF) leak and/ or orbital damage.

External frontoethmoidectomy• Infection Primary operation site• CSF leak• Webbing• Diplopia• Osteoplastic flap Cosmoses, frontal bossing, depression of bone CSF leak• Infection Primary operation siteFatAbdominal woundLaceration of duraNasal skin necrosis

• CT scanning is the best investigative tool and an endonasal endoscopic approach is the first line of treatment, as long as the mucocoele can be accessed and widely marsupialized.

• When required, a combined external and endoscopic approach avoids the need for artificial stenting.

• A pyocoele with acute orbital symptoms requires emergency surgery.