No increase in IgG4-positive plasma cells in limbal Rosai-Dorfman disease

Abstract

Purpose: Extranodal Rosai-Dorfman disease is a rare benign condition recently reported to sometimes show features of IgG4-related disease. The purpose of this study was to describe the corneal-limbal manifestation of the entity and to investigate whether numerous IgG4-positive plasma cells are associated with the disease at this site.

Methods: This is an interventional retrospective small case series.

Results: Two patients presenting with painless limbal mass lesions underwent total excisional biopsy with anterior lamellar keratoplasty for diagnostic and therapeutic purposes. Histopathologic evaluation of the specimens revealed inflammatory lesions containing atypical S100-immunoreactive histiocytes diagnostic of Rosai-Dorfman disease, but not an increase in the IgG4-positive plasma cells. Point mutations (V600E) in the BRAF oncogene were absent.

Conclusions: Rosai-Dorfmann disease should be considered in the differential diagnosis of limbal mass lesions. Involvement at this site was not associated with BRAF mutation or IgG4 abnormalities in the cases examined.

FIGURE 1

A and B, Slit-lamp photography shows an inferonasal corneal limbal mass with neovascularization and conjunctivalization. C, Histological examination revealed an atypical histiocytic infiltrate present in the substantia propria with associated chronic inflammation (H&E stain, original magnification ×100). D, Immunohistochemistry for S100 protein showing cytoplasmic immunoreactivity in the histiocytes (original magnification ×400). E and F, Although numerous IgG-positive plasma cells were noted, IgG4-positive plasma cells were very rare with none in this field (100×).

FIGURE 2

A, A Pink elevated, well-defined limbal nodule with dilated blood vessels. B, Histological examination revealed an atypical histiocytic infiltrate in the substantia propria, with epithelium at the top of the field (H&E stain, original magnification ×100). C, Engulfed lymphocytes (emperipolesis, arrow) could be found within the cytoplasm of some of the enlarged histiocytes (H&E, original magnification ×1000). D and E, S100 Immunohistochemistry showing cytoplasmic immunoreactivity in the histiocytes, some with phagocytized lymphocytes (arrow). F, CD1a immunostains were negative (original magnification ×100).