Spectrum of B-cell neoplasms associated with immunoglobulin G4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) has rarely been associated with lymphoid neoplasms, the spectrum of which remains unclear. B-cell lymphoid neoplasms (LN) associated with IgG4-RD diagnosed in a 4-year period were analysed. There were five men and three women at a median age of 76.5 (52-90) years; three with synchronous IgG4-RD and LN; three with IgG4-RD preceding LN by 2, 3, and 22 years; and two with LN preceding IgG4-RD by 2.5 and 7 years. All patients presented with disseminated lymphadenopathy. Monoclonal gammopathy of undetermined significance (MGUS)/smouldering multiple myeloma (SMM) was found in three patients, all with an IgGκ paraprotein. Levels of IgGκ and IgG4 correlated. Diffuse large B-cell lymphoma (DLBCL) was found in three patients, with one case showing co-existing lymphoma and IgG4-RD in the same lymph node biopsy. The remaining two cases were marginal zone lymphoma (MZL) developing in a lacrimal gland previously involved by IgG4-RD; and nodular lymphocyte predominant Hodgkin lymphoma (NLP-HL) diagnosed in a lymph node with concomitant IgG4-RD. Low-dose continuous prednisolone was given for MGUS/SMM, with both monoclonal IgGκ and IgG4 responding. Combination chemotherapy was given for DLBCL, with two patients achieving complete response and one patient dying from refractory lymphoma. The patient with MZL refused treatment, whereas the case of NLP-HL responded completely to chemotherapy. Our findings together with previous observations suggest that IgG4-RD has an increased risk of B-cell neoplasms. Patients with IgG4-RD presenting with lymphadenopathy require vigorous investigations to exclude lymphoid neoplasms.