The difference in anatomical and invasive characteristics between primary and secondary paranasal sinus mucoceles

Objective: To evaluate the difference in anatomical and invasive characteristics of primary and secondary paranasal sinus mucoceles. Study Design: A retrospective chart review at a tertiary academic center. Results: During a 10-year period, 57 and 109 patients with primary and secondary mucoceles were enrolled, respectively. Thirty-five (61.4%) of primary and 26 (23.9%) of secondary mucoceles had intraorbital extension (IOE), while seven (12.3%) of primary and two (1.8%) of secondary mucoceles had intracranial extension (ICE). In comparison of tendency for IOE or ICE between primary and secondary mucoceles in each sinus, only primary maxillary mucoceles were shown to have a significantly higher probability of IOE than secondary maxillary mucoceles. Among primary mucoceles, ethmoid mucoceles had a significantly greater capability to cause IOE while maxillary mucoceles had the least. Among secondary mucoceles, frontal and ethmoid mucoceles had a greater ability to cause IOE while maxillary mucoceles had the least. As for ICE, sphenoid mucoceles had a greater potential in both groups. Conclusions: Primary mucoceles seem to have a greater potential to cause IOE and ICE than secondary mucoceles. In both groups, ethmoid mucoceles have a higher potential of IOE, while sphenoid mucoceles have a greater tendency to cause ICE.