IgG4-Related Disease: A Diagnosis After 15 Years.

Abstract

A 52-year-old man with long-standing pancreatitis presented with 6 months of variable right periocular swelling. Fifteen years earlier, a right lacrimal gland biopsy showed reactive lymphoid hyperplasia (Fig. A), the inflammation settling with systemic corticosteroids.FIG.: IgG4: A final diagnosis after 15 years: (A) hematoxylin and eosin staining—reactive lymphoid hyperplasia; (B) MRI—enhancing diffuse changes within the right orbital fat; (C) MRI—bilateral infraorbital nerve enlargement; and (D) staining for IgG4-related disease—predominance of IgG4 plasma cells.Recent MRI showed enhancing diffuse changes within the right orbital fat and bilateral infraorbital-nerve enlargement (Fig. B,C). As enlargement of periorbital sensory nerves with orbital inflammation is suggestive of IgG4-related disease, restaining of the earlier biopsy revealed a predominance of IgG4 plasma-cells (Fig. D) and confirmed the diagnosis of IgG4-related disease. In the second look on the histology slides from 15 years ago, a dense lymphoplasmacytic infiltrate, fibrosis, arranged in a storiform pattern, and obliterative phlebitis were seen. Those histological features can be characteristic for IgG4-related disease. Morphologically, reactive lymphoid hyperplasia looks like IgG4-related disease, but immunostaining for plasma-cell subclasses helps differentiate the 2. Therefore, in cases of reactive lymphoid hyperplasia, it is recommended to also do a staining for IgG4-related disease to diagnose the disease accurately.