Inflammatory pseudotumour affecting the lung and orbit.

This report describes a rare case of inflammatory pseudotumour arising metachronously from the orbit and lung. A 78-year-old man with a 7-year history of orbital inflammatory pseudotumour developed a solitary mass in the right lung. Serological studies showed elevated levels of IgG and antinuclear antigen. Wedge resection of the lesion was performed under VATS. Histology showed that lymphoplasmacytic infiltration with dense fibrosis and flow cytometry proved these cells to be polyclonal. Immunostaining revealed numerous IgG4-positive plasma cells diffusely infiltrating the lesion.