Ocular adnexal IgG4‐related disease: comparative analysis with mucosa‐associated lymphoid tissue lymphoma and other chronic inflammatory conditions

Abstract

Go H, Kim J E, Kim Y A, Chung H K, Khwarg S I, Kim C‐W & Jeon Y K (2012) Histopathology 60, 296–312 Ocular adnexal IgG4‐related disease: comparative analysis with mucosa‐associated lymphoid tissue lymphoma and other chronic inflammatory conditions Aims: Making a differential diagnosis of IgG4‐related disease from mucosa‐associated lymphoid tissue (MALT) lymphoma or any other chronic inflammation is often challenging. Moreover, the association with secondary lymphoma of ocular adnexal IgG4‐related disease needs to be elucidated. Methods and results: We investigated 14 cases of IgG4‐related disease, nine MALT lymphomas and 12 other chronic inflammations involving the lacrimal gland and orbit. Bilateral involvement was frequent in IgG4‐related diseases. The number of IgG4‐positive cells and the ratio of IgG4/IgG‐positive cells were higher in patients with IgG4‐related disease than in those with MALT lymphoma (P = 0.016; P < 0.001) and other types of inflammation (P < 0.001; P < 0.001). Monoclonal B cell proliferation was suspected in two cases (14.3%) of IgG4‐related disease. One of these patients also displayed monomorphous features suggesting secondary MALT lymphoma. In the other case, κ‐chain restriction in IgG4‐positive cells was observed, raising the possibility of IgG4‐producing MALT lymphoma. Trisomy 3, trisomy 18 or MALT1 translocation was observed in none of the IgG4‐related cases. Regulatory T‐cell infiltration was higher in cases of IgG4‐related disease than in MALT lymphomas (P < 0.001) and other types of inflammation (P = 0.006). Conclusions: Some genetically and morphologically complicated cases of ocular adnexal IgG4‐related disease emphasize the need for in‐depth studies to differentiate this disease from MALT lymphoma, and to exclude secondary lymphoma.