Persistent Pneumosinus Dilatans Refractory to Endoscopic Frontal Sinus Surgery: A Case Report

Pneumosinus dilatans (PD) is a rare clinical entity involving expansion of the paranasal sinuses. While the pathogenesis of PD is not fully understood, the prevailing theory involves a “ball-valve” mechanism in which obstruction of sinus outflow leads to progressive air cell expansion. Typically, the progression of PD can be halted with endoscopic sinus surgery to relieve any outflow obstruction. In this report, the authors present a case of a patient with progressive expansion of the frontal sinus refractory to endoscopic sinus surgery. The patient ultimately required excision of the anterior table of the frontal sinus and reconstruction with a custom polyetheretherketone implant. This case highlights the variability of PD presentation and how treatment and reconstruction must be tailored to each patient’s unique presentation.