Immunoglobulin G4-related diseases mimics Rosai-Dorfman diseases: a series of 6 cases in China

Abstract

Objective To summarize the clinical and pathologic characteristics of patients with Rosai-Dorfman disease (RDD) mimicking immunoglobulin (Ig) G4-related disease (IgG4-RD). Methods Retros- pectively analyze the clinical manifestations, laboratory tests, pathologic features, treatment and prognosis of RDD patients whose clinical presentations mimicked IgG4-RD in Peking Union Medical College Hospital during January 2015 to June 2017. Results Six RDD patients mimicking IgG4-RD were described, which accounted for 1.5% of the 450 registered IgG4-RD patients. All patients were male, with the median age of 53 year and the median disease duration of 12 months. All patients had extra-nodal involvements, of which the locations included spinal cord (3/6), intracranial (2/6), skin (2/6) and liver (1/6). Increased serum IgG4 (>1 350 mg/L) was found in 4 cases (1 360-6 410 mg/L). Seven specimens were obtained from these patients. The number of IgG4-positive plasma cells was found to be more than 50 per HPF in 3 cases, 30 per HPF in 1 case. The IgG4/IgG ratio was 40% in 2 specimens, between 10% and 30% in 2 specimens and 10% in 2 specimens. All patients were treated by glucocorticoids and 4 of them were treated with combined cyclophosphamide. Five patients got partial remission by these treatments while 1 patient withdrew from further follow up. Conclusion RDD is one of the mimics of IgG4-RD. There are several differences in lab tests and pathologic features between RDD and IgG4-RD. Before the IgG4-RD is diagnosed, RDD should be excluded by specific pathologic manifestations at the first place. Key words: Histiocytosis, Sinus; Pathologic processes; Prognosis; Immunoglobulin G4-related diseases