Idiopathic inflammatory diseases of orbit and ocular adnexa: Histopathological and immunochemical analysis

Purpose: To present histopathological and immunohistochemical analysis of idiopathic inflammatory diseases of orbit and ocular adnexa. Methods: Design- A retrospective laboratory-based study. The study was carried out in an ocular pathology laboratory in a tertiary institute of northeast India where analysis of 93 cases was done in 5 years, during the period from 2011 to 2016. Hematoxylin--eosin and special stains were done for the diagnoses. Immunohistochemistry (IHC) panel was also carried out. For infectious pathology, Grocott's methenamine silver (GMS) stain for fungus, tissue Gram's stain for bacteria's, and acid-fast stains for tubercular bacilli were done. IHC panels were done for CD 20 (B-cells), CD-3 (T-cells), CD-45 (Leukocyte common antigen, LCA), BCL-2, CD-138 (Plasma cells), Kappa, Lambda, IgG-4 in tissue, IgG-4 in serum, etc. IHCs were done using kit methods (standardized) and adequate controls were taken for each sample. Results: 93 cases of nonspecific orbital inflammation were reported out of 1,467 specimens. Orbital pseudotumors (idiopathic orbital inflammatory disease, IOID) were seen in 27 cases (sclerosing variety-6); benign lymphoid hyperplasia in two cases; reactive lymphoid hyperplasia in 10 cases; atypical plasma lymphoproliferative reactive (polyclonal immunophenotypically, IgG4 negative) lesions in four cases; IgG-4 related disease in one case; nonspecific inflammatory reactions (conjunctiva, sclera, and lid) in 49 cases. In all the diagnoses, infections and lymphomas were excluded. Conclusion: Biopsy supported study on nonspecific orbital inflammation was important to know the pattern.