Treatment and Prognosis of Inflammatory Pseudotumor of the Skull Base

Background  Inflammatory pseudotumor (IPT) of the skull base is a rare, locally destructive lesion managed with a variety of treatments. We explore the impact of treatment on outcome and assess the prognosis of IPT. Methods  This is a retrospective review of IPT of the skull base at a tertiary academic medical center. The primary outcome was radiographic progression after treatment. Outcome versus tumor location was also examined and a prognostic model was developed using a logistic regression. Results  The demographics of 21 patients with IPT are reported. Treatment consisted of corticosteroids (in 80.1% of patients), disease modifying antirheumatic drugs (DMARDs; 33.3%), surgical resection (28.6%), radiation (23.8%), antibiotics (14.3%), chemotherapy (rituximab; 9.5%), and antivirals (4.8%). At 50.7 months, 50.8% had radiographic progression. Local therapy trended toward having a better response than systemic therapy ( p  = 0.60). IPT of the orbit required 2.4 treatment modalities, compared with 2.0 for pharyngeal IPT, and 1.3 for posterior skull base masses ( p  = 0.14). A total of 75% orbital IPT underwent radiographic progression, compared with 71% of pharyngeal IPT and 50% of posterior skull base masses ( p  = 0.62). Sixteen patients were used to create the logistic model of radiographic progression. The Cox-Snell R ² was 0.71 ( p  = 0.03). No individual variables were statistically significant. Conclusion  To our knowledge, this is among the largest sample of cases describing the presentation, treatment, and prognosis of IPT of the skull base. Our data suggest that there may be an improved response with local therapy over systemic therapy and better prognosis among posterolateral skull base masses.