MUCOCELES OF THE PARANASAL SINUSES – BEYOND THE TYPICAL PRESENTATION: ORBITAL AND INTRACRANIAL COMPLICATIONS
Luís B. Cardoso
Introduction: Mucoceles are cystic cavities with mucus and lined by pseudo-stratified columnar epithelium that develop in paranasal sinuses. Sinus ostia obstruction may occur as a result of anomalous anatomy, inflammation, trauma, tumours, allergy or past surgical procedures. Obstruction leads to the entrapment of mucus-secreting cells, which encase as the cells continue to expel mucus. As the mucocele enlarges, it becomes more space occupying and compressive, leading to demineralization and erosion of the sinus walls, allowing the mucocele to protrude into adjacent structures.
Case presentation: We made the follow up of 4 patients with complicated mucoceles at presentation. A 75-year-old woman who came to the emergency with headache complaints and recent behavioural changes; had a large frontal osteoma that led to a right frontal mucocele which, in turn, extended intracranially with pneumocephalus and mass effect over the brain parenchyma leading to frontal lobe syndrome. A 54-year-old woman with a frontal meningioma that extended to anterior ethmoid cells and frontal recess, developed a mucocele of the left frontal sinus with mass effect over the orbit and proptosis. A 69-year-old man with chronic sinonasal polyposis and previous functional endoscopic procedures that presented with relapsed frontal mucocele with mass effect over the extraocular muscles and proptosis. A 43-year-old woman with Wegener granulomatosis, presented with extensive sinonasal disease developing right frontal and ethmoidal mucoceles with bulging of the lamina papyracea through the orbit.
Conclusions: Although benign, the slowly expanding mucoceles may lead to erosion of the bony sinus walls and complicate with protrusion into the orbits, nasopharynx or rarely the cranium. Surgery is the required treatment for complete eradication and reestablishment of normal sinus drainage; reconstruction of bony defects from thinning or erosion may be required. The recurrence rates are high and follow up over several years is preferred.