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.