1 Paranasal Sinus MucoceleIntern 李欣學

2 Definition Epithelial lined mucus-containing sac completely filling a paranasal sinus and capable of expansion. May cause bone erosion

3 Location Frontal sinus (60%) Ethmoid sinus (25%) Maxillary sinus (10%)Sphenoid sinus (5%) Rao VM, Sharma D, Madan A. Imaging of frontal sinus disease: concepts, interpretation, and technology. Otolaryngol Clin North Am 2001 Feb;34(1):23-39.

4 Clinical PresentationsPain Exophthalmos Diplopia Loss of vision An erosive mucocele may lead to meningitis, meningoencephalitis, pneumocephalus, brain abscess, seizures or CSF fistulas

5 Etiology Infection Trauma Nasal polyposis TumorPrevious surgery Fracture Nasal polyposis Tumor Benign Malignant Hypersecretion of mucus

6 Plain X-ray Frontal sinus mucoceles can be diagnosedBut mucoceles in the maxillary antrum, sphenoid, and ethmoid sinuses may be missed.

7 CT CT Contrast Enhanced CT Optimum methodairless, homogenous mucoid density (10–18 HU) cystic lesion Higher attenuation in long-standing mucoceles (20-40 HU) Contrast Enhanced CT Lining membrane enhancement

8 MRI Indicated when there’s uncertainty following the use of CT.Usually Low T1 signal High T2 signal Variable signal intensity due to Presence of blood content Degree of dehydration

9 Gadolinium-enhanced MRIUseful for demonstrating secondary mucocele Rim enhancement

10 台灣特有種 莫氏樹蛙 (Rhacophorus moltrechti)

11 Frontal Mucoceles Loss of normal scalloped marginErosion of supra-orbital ridge Extension to opposite side frontal sinus or posteriorly

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14 Ethmoid Mucoceles More common in the anterior group of ethmoid cellsDifficult to detect on plain film Clinical presentation Palpable mass at medical canthus Proptosis (91%) Lateral displacement of the globe (55%) Inferior displacement of the globe (59%) Epiphora (when invading lacrimal duct)

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16 Sphenoid Mucoceles May involve Clinical presentation Optic nerveCavernous sinus Oculomotor nerves Clinical presentation Headache + Blurred vision or diplopia Followed by visual loss

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18 Maxillary Mucoceles Clinical presentation Nasal obstructionNeuralgia of maxillary n. (CN V-II) Cheek deformity Diplopia

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21 Differentiation from TumorEnhancement with contrast Behavior of bone destruction

22 Reference Glyn Lloyd et al: Optimum imaging for mucocele, Journal of Laryngology and Otology 2000 March; 114(3) ,. Gavioli C, Grasso DL, Carinci F, Amoroso C, Pastore A. Mucoceles of the frontal sinus: Clinical and therapeutical considerations. Minerva Stomatol 2002 Sep;51(9): Rao VM, Sharma D, Madan A. Imaging of frontal sinus disease: concepts, interpretation, and technology. Otolaryngol Clin North Am 2001 Feb;34(1):23-39.

23 Thank You for Your Attention!台灣特有種 橙腹樹蛙 Orange-bellied Treefrogs (Rhacophorus aurantiventris)