An inflammatory pseudotumor of the liver in a patient with reactive arthritis

A rare case of an inflammatory pseudotumor (IPT) of the liver with reactive arthritis (ReA) is herein described. A 34-year-old woman presented with post-infectious ReA in the bilateral knees and foot joints. As the primary infected site for ReA could not be determined, a systemic survey revealed an IPT in her liver, which was diagnosed histologically. The arthritis and the tumor regressed simultaneously after being treated by indomethacin farnesil 400 mg/day. Although the exact etiology of IPT or ReA still remains unknown, it is hypothesized that the same pathogenetic mechanisms may be involved in the development of IPT and ReA.