Abstract

The spectrum of IgG4-related disease (RD) has expanded considerably in the last decade, with new focus on cutaneous findings as a harbinger of this systemic fibroinflammatory disorder. Diagnostic criteria for cutaneous IgG4-RD have been proposed, however, cases with incomplete or exceptional features intersect broadly with other B-cell lymphoproliferative disorders, including primary cutaneous marginal zone lymphoma (pcMZL) with plasmacytic differentiation. We present a series of 3 patients presenting initially with suspected pcMZL who were found to have cutaneous IgG4 rich plasma cell infiltrates and elevated serum IgG4. We review what is known regarding the salient features of IgG4-RD and simulants in skin.

Financial Disclosure:
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