Inflammatory Pseudotumor in the Parapharyngeal Space: Is It Possible to Diagnose by Exclusion?

Inflammatory pseudotumor (IP) is a rare pathologic condition that easily can be confounded with malignancy. The clinical presentation depends on the site of occurrence and the radiological or laboratory findings are not specific. Diagnosis can be established only with histology. We report a case of a 64-year-old woman with IP in an uncommon localization, the parapharyngeal space extending to skull base. Although the diagnosis was not certain after histopathological examination, broad diagnostic workup helped to exclude malignancy or bacterial infection and led to diagnosis of an IP by exclusion. We observed a good clinical and radiological regression of symptoms after administration of oral immunosuppressants, confirming the immunological mechanism of the disease.