Inflammatory pseudotumor presenting as fever of unknown origin.

Inflammatory pseudotumor (IPT) is an uncommon benign neoplasm of uncertain etiology that classically has been associated with the lung, where it is generally asymptomatic. In recent years, IPT has been increasingly recognized in other sites. Hepatic, abdominal, and pelvic IPTs produce a spectrum of nonspecific symptoms including fever, malaise, anemia, and weight loss. Because prolonged fever is a prominent feature of extrapulmonary IPT, patients with this condition may first come to the attention of specialists in infectious diseases. We describe an illustrative case of pelvic IPT and discuss its presentation, diagnosis, and treatment; we also suggest that infectious disease specialists should be familiar with this entity as a possible diagnosis for patients with fever of unknown origin.