Pulmonary Hyalinizing Granuloma With Associated Elevation in Serum and Tissue IgG4 Occurring in a Patient With a History of Sarcoidosis

Abstract

Pulmonary hyalinizing granulomas (PHGs) are unusual fibrosclerotic inflammatory lung lesions. The organ-based manifestations of the recently defined IgG4-related sclerosing disease typically show dense fibrosis and heavy lymphoplasmacytic infiltrates. IgG4-related sclerosing disease is also defined by increased serum IgG4 levels and increased tissue levels of IgG4-positive plasma cells. The morphologic features of PHG overlap with those seen in IgG4-related sclerosing disease, and this suggests that PHG may be a form of IgG4-related sclerosing disease. We present a case of a 51-year-old man with a history of sarcoidosis who presented with slowly enlarging pulmonary nodules. Histologic evaluation of one of the nodules yielded a diagnosis of PHG. Further investigation demonstrated both elevated serum IgG4 and elevated tissue IgG4-positive plasma cells in the PHG. In previous reports, lesions that are now considered part of IgG4-related sclerosing disease were documented in patients also diagnosed with PHG, although these reports date from before the description of IgG4 sclerosing disease. This case provides the first definitive evidence that PHG is part of the spectrum of IgG4-related sclerosing disease.

Lymph node granulomas in immunoglobulin G4‐related disease

“…Examples include orbital xanthogranuloma and granuloma faciale . Pulmonary hyalinizing granuloma is now recognized as a manifestation of IgG4‐RD but, despite its name, is not characterized by the presence of granulomas within the nodular lung lesions . The two cases that we report provide additional evidence that granulomas may be present within tissues affected by IgG4‐RD, contrary to the previously held view that identification of granulomas would usually make a diagnosis of IgG4‐RD unlikely.…”

Pulmonary Hyalinizing Granuloma Associated with Idiopathic Thrombocytopenic Purpura

“…Specifically, associations have been reported with fungal and mycobacterial lung disease as well as with rheumatoid arthritis, uveitis, lupus-like anticoagulant, Morvan's syndrome, sclerosing mediastinitis, idiopathic systemic fibrosis, sarcoidosis and IgG4-related sclerosing disease. [789] An association of PHG with lymphoproliferative disease (lymphoma and Castleman's) has also been demonstrated. [7]…”

A 40-Year-Old Woman With Multiple Pulmonary Nodules

“…9 PHG was reported in the patient with sarcoidosis and IgG4-related systemic sclerosing disease, which demonstrated increased serum IgG4 levels and elevated tissue IgG4-positive plasma cells in the PHG nodule. 10 Th ey shared the similar spectrum of manifestations, including sclerosing mediastinitis and retroperitoneal fi brosis, which might be explained from the same pathogenesis hypothesis. The Yousem and Hochholzer 2 series mentioned that sclerosing infl ammatory pseudotumors closely resemble PHG because four cases had lesions adjacent to PHG that were indistinguishable from infl ammatory pseudotumors and plasma cell granuloma.…”