Adenoma and Adenocarcinoma of the Retinal Pigment Epithelium: A Review of 51 Consecutive Patients

Advances in multimodal imaging for diagnosis of pigmented ocular fundus lesions

Pigmented ocular fundus lesions can range from benign to malignant. While observation is reasonable for asymptomatic benign lesions, early recognition of tumours that are vision or life threatening is critical for long-term prognosis. With recent advances and increased accessibility of multimodal imaging, it is important that providers understand how to best use these tools to detect tumours that require early referral to subspecialty centres. This review aims to provide an overview of pigmented ocular fundus lesions and their defining characteristics using multimodal imaging. We cover the spectrum of pigmented ocular fundus lesions, including freckle and focal aggregates of normal or near-normal uveal melanocytes, retinal pigment epithelium (RPE) hyperplasia, congenital hypertrophy of the RPE, RPE hamartoma associated with familial adenomatous polyposis, congenital simple hamartoma of the RPE, combined hamartoma of the retina and RPE (congenital hypertrophy of the RPE), choroidal nevus, melanocytosis, melanocytoma, melanoma, adenoma, and RPE adenocarcinoma. We describe key diagnostic features using multimodal imaging modalities of ultra-widefield fundus photography, fundus autofluorescence, optical coherence tomography (OCT), enhanced-depth imaging OCT, ultrasonography, fluorescein angiography, indocyanine green angiography, and OCT angiography (OCTA), with particular attention to diagnostic features that could be missed on fundus examination alone. Finally, we review what is on the horizon, including applications of artificial intelligence. Through skilled application of current and emerging imaging technologies, earlier detection of sight- and life-threatening melanocytic ocular fundus tumours can lead to improved patient prognosis.

Nonpigmented Adenoma of the Retinal Pigment Epithelium Mimicking a Retinal Vasoproliferative Tumor Managed With Endoresection

Purpose: To present a case with signs suggestive of a retinal vasoproliferative tumor. Methods: A case report was evaluated and a surgical video presented. Results: A 61-year-old White man presented with an amelanotic retinal tumor associated with exudation, retinal edema, and overlying telangiectatic vessels, suggestive of a retinal vasoproliferative tumor. Standardized echography showed an irregular mass with medium-to-high internal reflectivity and internal calcification, which suggested chronicity. He was initially treated for an exudative retinal detachment (RD) in the context of a presumed vasoproliferative tumor but later developed combined exudative and rhegmatogenous RD, prompting surgical repair with tumor endoresection. Pathology showed nonpigmented adenoma of the retinal pigment epithelium (RPE). Conclusions: Nonpigmented adenoma of the RPE is a rare tumor, and its clinical similarity to a vasoproliferative tumor should be noted. Endoresection may be considered in cases resulting in RD.

New Insights into Dose-Dependent Effects of Curcumin on ARPE-19 Cells

Opposing dose-dependent effects of curcumin (Cur) have been documented in Retinal Pigment Epithelium (RPE); therefore, to shed the light on the mechanisms of action is crucial for ophthalmic applications. On this basis we explored new insights about the dose-dependent mechanisms triggered by Cur in human retinal pigment epithelial cells (ARPE-19). Three concentrations (0.01 mM; 0.05 mM; 0.1 mM) of Cur were tested, followed by morphological, molecular, and functional analysis of the cells. Cur 0.01 mM promotes a significant increase in cell proliferation, not affecting cell cycle progression and apoptosis; by contrast, Cur 0.05 mM and 0.1 mM block cellular proliferation and trigger S-phase cell cycle arrest without inducing apoptosis. The observation of neuronal-like morphological changes in Cur 0.05 mM and 0.1 mM were not associated with neuronal differentiation, as observed by the quantification of Neurofilament-200 and by the analysis of voltage-dependent currents by patch clamp. Evaluation of autophagic markers LC3BII and p62 revealed significant modulations, suggesting an important activation of autophagy in ARPE-19 cells treated with Cur 0.05 mM and Cur 0.1 mM; conversely, Cur 0.01 mM did not affect autophagy. Altogether, our findings show new dose-dependent mechanisms of action of Cur that suggest a wide therapeutic application in ocular diseases with different pathogenesis (i.e., proliferative vitreoretinopathy or Age-Related Macular Degeneration).

Color Doppler imaging characteristics of RPE neoplasms: A study of 17 cases

Purpose

To report the color Doppler imaging (CDI) features of 17 patients with retinal pigment epithelium (RPE) neoplasms.

Design

Retrospective, observational case series.

Participants

Seventeen patients with RPE adenoma/adenocarcinoma.

Methods

Contrast-enhanced color Doppler ultrasonography (CDU) was performed in 16 patients with RPE adenoma and in one patient with adenocarcinoma.

Result

All 17 RPE neoplasms showed well-defined margins. An oval mass was observed in 11 tumors, a lenticular-shaped mass in four tumors, and a flat mass in two tumors. On CDI, RPE lesions showed homogeneous reflectivity of moderate intensity with no choroidal excavation. After the contrast-enhanced administration of sulfur hexafluoride, mild enhancement was identified in six tumors and moderate enhancement in 11 tumors. In all 17 RPE neoplasms, contrast-enhanced CDU time-intensity curves (TICs) exhibited fast fill-in and slow washout-shaped curves with the dominant vessel within RPE lesions. A "black-linear" sign (defined as a low signal intensity-linear zone located between the tumor and enhanced choroid on CDI) was noted in all 17 patients with RPE neoplasms.

Conclusions

This preliminary study noted a "black-linear" sign on CDI of RPE lesions for the first time. The novel sign may be a diagnostic characteristic of RPE neoplasms and may help to distinguish this rare entity from uveal melanomas (UMs).

Retinal Pigment Epithelium Adenoma and Adenocarcinoma: A Review

Adenoma and adenocarcinoma of the retinal pigment epithelium (RPE) are rare intraocular tumours that are often misdiagnosed as posterior uveal melanoma or other simulating lesions. It is important to be able to differentiate these tumours from melanoma for 3 reasons. First, an inability to rule out melanoma often tilts the management towards enucleation. Second, management options like radiotherapy and local resection which work well for melanoma may not be easily applied to these tumours. Third, and most importantly, patients with melanoma need a lifetime follow-up to rule out metastases (metastatic dormancy) whereas RPE tumours hardly metastasize. An abruptly elevated, often deeply pigmented tumour, with a prominent retinal feeding artery and a draining vein causing exudation, should raise a suspicion of RPE tumours. RPE tumours have a remarkable local invasive potential but a low metastatic potential. Most RPE tumours require treatment due to local complications. Small, asymptomatic tumours can be generally observed. Enucleation is still the gold standard of treatment, although local resection has been reported in selected cases with good results. Here, we provide a comprehensive review of the demographic, clinical, and imaging features of true acquired neoplasms of the RPE, namely adenoma and adenocarcinoma, the ways to differentiate them from melanoma, their clinical course and prognosis, and Options for their management.