Abstract
Purpose :
To report clinical and pathological characteristics of Idiopathic orbital inflammation(IOI) and ocular adnexal mucosa- associated lymphoid tissue (MALT) lymphoma with IgG4-positive plasma cells.
Methods :
A retrospective histopathological review and clinical case series. A total of 51 biopsy samples from January 2005 through December 2015 were used in this study, including 21 cases of biopsy-confirmed IOI and 30 cases of biopsy-confirmed ocular adnexal MALT lymphoma. Retrospective immunohistochemical studies were performed to estimate the IgG4 and IgG4/IgG ratios. Histopathologic features, demographic and clinical data, radiologic findings, treatment and follow-up information for each patient were analyzed.
Results :
Among IOI, six (17.2%) of the 21 patients were diagnosed as ‘probable’ ocular adnexal IgG4-RD and thirteen (43.3%) of the 30 patients were diagnosed as MALT lymphoma with IgG4-positive plasma cells. The six cases of the IgG4-positive MALT lymphoma group had contralateral chronic inflammation lesion infiltrated by IgG4 –positive plasma cells (p = 0.007). Conjunctival involvement was 69% of the IgG4-positive MALT lymphoma cases. Bilateral involvement of the ocular adnexa was significantly (p = 0.02) more frequent among IgG4-positive MALT lymphoma patients than that in IgG4-positive IOI patients. The response rates to radiation and chemotherapy were similar to each other between IgG4-positive and negative MALT lymphoma group. Recurrence rate in the IgG4-positive group was higher (p = 0.05) than that in the IgG4-negative group, but not significantly.
Conclusions :
Patients with IgG4-positive chronic inflammatory lesion might be at an increased risk of developing ocular adnexal MALT lymphoma and ocular adnexal MALT lymphoma with IgG4 positive plasma cells. They have unique histopathological and clinical characteristics that overlap with those of ocular adnexal IgG4-RD. Furthermore, ocular adnexal MALT lymphoma, IgG4-RD, and chronic inflammatory lesions in the ocular adnexa are clinically and radiologically indistinguishable from each other. Tissue biopsy and IgG4-immunostaining are required for all cases even if the lesion involves conjunctiva because conjunctiva is the second most frequent site of MALT lymphoma origin and it is able to be diagnosed as IgG4-RD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.