Immunohistochemical Analysis of a Vitreous Membrane Removed from a Patient with Incontinentia Pigmenti-Related Retinal Detachment

Abstract

This is a case history of a 23-year-old woman suffering from incontinentia pigmenti (IP). The patient's vision in the left eye started to deteriorate due to cataract progression at the age of 22, and by the age of 23, it dropped from 0.9 to 0.04. Ultrasound examination confirmed tractional vitreoretinal membranes. Vitrectomy was performed, therefore, on her left eye. The histological evaluation of vitreous membrane revealed a complex immunophenotype (positivity for glial fibrillary acidic protein (GFAP), vimentin, S-100, anti-pan cytokeratin antibody (AE/AE3), and smooth muscle-specific actin (SMA) to various extents). The right eye remained unsymptomatic throughout this course. Besides being the first to analyze the tractional vitreoretinal membrane in IP with immunohistochemical methods, this case study points out that extreme cases of asymmetric side involvement in IP do exist, even to the point of one eye being completely unsymptomatic.

Keywords: epiretinal membrane; hereditary diseases; immunohistochemistry; incontinentia pigmenti.

Figure 1

Preoperative optical coherence tomography (OCT) and ultrasound B-scans. The top left scan shows the normal macula of the right eye, and on the top right, the slightly thicker macula, flattened foveal depression, and a faint epimacular membrane of the left eye can be seen. The bottom left OCT and the bottom right ultrasound image demonstrate one of the tractional membranes in the left eye.

Figure 2

Histological and immunohistochemical features of vitreous membrane. Thin, membrane-like tissue was observed, composed of scattered cells embedded in an eosinophilic, slightly periodic acid-Schiff (PAS)-positive substance. The cells had small rounded or elongated nuclei without atypia, scanty cytoplasm, and indistinct cell borders (hematoxylin and eosin (H&E)). The cells did not rest on basement membrane (PAS). Occasionally, brownish-black pigment granules were observed in a few cells (arrows) and in the adjacent extracellular substance, shown in the cluster of differentiation 34 (CD34)-stained part. The cytoplasm of the cells and the extracellular substance strongly and diffusely reacted with GFAP and vimentin; the S-100 staining decorated the majority of nuclei and occasionally the extracellular substance. Focal cytoplasmic and extracellular substance positivity for anti-pan cytokeratin antibody (AE/AE3) and smooth muscle-specific actin (SMA; not shown) was noted. The human melanoma black-45 (HMB-45), cluster of differentiation 68 (CD68), cytokeratin 18 (CK18), cytokeratin 19 (CK19), and cluster of differentiation 34 (CD34) reactions were negative. Scale bars: 100 µm.