Mucoceles of the Paranasal Sinuses

Overview Mucoceles of the Paranasal Sinuses Francis T.K. Ling, MD BSc Department of Otolaryngology – Grand Rounds University of Ottawa Wednesday, January 28th 2004 Introduction • Definition: • Anatomy and Development • Physiology and Pathophysiology • Epidemiology • Clinical Features • Treatment • Case Presentations Introduction • Mucoceles known for > 100 years • Epithelial lined mucous-containing sac completely filling a paranasal sinus • Capable of expansion by virtue of bone resorption and new bone formation • 1725: Dezeimeris first described frontal mucoceles • 1818: Langenbeck commented on clinical complaints and symptoms • “hydatids” • 1890: Rollett introduced the term “mucocele” • Most common lesion causing expansion of paranasal sinuses Anatomy and Development • Maxillary sinuses • Ethmoid sinuses • Sphenoid sinus • Frontal sinuses Anatomy and Development • Maxillary Sinuses • Occupies body of maxilla • First to develop in the human fetus • Biphasic growth: • 3 years • 7 years to adolescence • Average volume 14.75 ml • Drains into middle meatus via maxillary ostium 1 Anatomy and Development • Ethmoid Sinuses • Located in superior half of lateral nasal wall • Development begins during 3rd-4th month of fetal development • Continue to grow through childhood until age 12 • Average volume 15 ml • Drainage: • Anterior: infundibulum or ethmoid bulla • Posterior: superior meatus Anatomy and Development • Frontal Sinuses • Frontal bone • Begins as evagination of frontal recess • Development begins at 2 ya and reaches adult size at 15-20 ya • Variable development: • 10% unilateral • 5% rudimentary • 4% absent • Drainage into frontal recess • 2-20 mm in length Physiology • Sinus lining: • Ciliated, pseudostratified, columnar epithelium • Mucous glands and goblet cells mucous blanket • “sol-gel” phase Anatomy and Development • Sphenoid sinus • In body of sphenoid bone • No significant sinus at birth • Development begins at 5 years • Final volume attained by 12-15 years • Average volume: 7.5 ml • Drainage: • Sphenoethmoidal recess Anatomy and Development • Frontal recess • Marked variation in configuration and attachment of uncinate process • Variable drainage patterns of frontal recess Physiology • Pattern of clearance: • Maxillary: floor stellate pattern along walls to natural ostium • Frontal: inward flow medially superior lateral floor frontal recess 2 Pathophysiology • Obstruction of sinus ostium or outflow tract • Inflammation (ie. Chronic sinusitis) • Trauma • Iatrogenic (eg. FESS) • Mass/Tumour (eg. Polyps, ostioma, malignancy, ostioma) • Obstruction of minor salivary gland located within lining of paranasal sinus • Eg. Mucous retention cyst of maxillary sinus Epidemiology • 3rd or 4th decade • M:F ~ 7:1 • 10-15 years to develop • Frontal > ethmoid > maxillary > sphenoid • Fronto-ethmoidal ~65% • Maxillary ~ 20% • Sphenoid ~1-8% • Posterior ethmoid ~1-6% • Uncommon locations: middle turbinate, pterygomaxillary space Clinical Presentation • Slow expansion • Patients asymptomatic for many years • May take 10 years or more to become symptomatic • Symptoms depend on location/type of mucocele and extent of bony erosion • In general: Pathophysiology • Bone resorption: • Epithelium continues to secrete causing expansion of the mucocele • Increased pressure devascularization of bone and osteolysis • Local inflammation secretion of cytokines • Fibroblasts PGE2 + IL-1 • Epithelial cells TNF alpha • Cause osteoclastic bone resorption Epidemiology • Rombaux et al (Belgium, 2000): • 178 mucoceles • Primitive mucoceles: 35% • Post-traumatic: 2.1% • Post-operative: 62.9% • Incidence after FESS not known Fronto-ethmoidal Mucocele • Most common clinically significant mucocele • Classification (Har-El, 2001) • Type 1: Limited to frontal sinus (+/- orbital extension) • Type 2: Frontoethmoid mucocele (+/- orbital extension) • Type 3: Erosion of posterior wall • A. Minimal or no intracranial extension • Headache and facial pressure common • Facial swelling with tenderness to palpation • Ocular and neurological problems • B. Major intracranial extension • Type 4 Erosion of anterior wall • Type 5 Erosion of both posterior and anterior wall • A. Minimal or no intracranial extension • B. Major intracranial extension 3 Fronto-ethmoidal Mucocele • General: • Frontal headache (common) and/or deep nasal pain • Frontal swelling +/- infection/draining fistula • Nasal obstruction and rhinorrea unusual ... - tailieumienphi.vn