A nonpigmented retinal pigment epithelium adenoma with retinitis pigmentosa:A case report

Retinal pigment epithelium (RPE) adenoma represents an extremely rare posterior segment tumor with frequent diagnostic challenges, commonly mimicking vasoproliferative tumors or amelanotic choroidal melanoma. This report details a novel case of peripheral nonpigmented RPE adenoma coexisting with retinitis pigmentosa (RP), highlighting diagnostic complexities in dual pathology presentation. A 77-year-old male presented to the Department of Ophthalmology at Shanghai General Hospital with a two-month history of progressive vision loss in his right eye. Best-corrected visual acuity (BCVA) was finger-counting (FC) in the right eye and 20/30 in the left. Bilateral fundus examination revealed mid-peripheral bone-spicule-like pigmentary deposits. In the right eye, a yellowish-white retinal mass was observed at the supratemporal vascular arcade, accompanied by retinal detachment extending into the macula. The patient underwent combined cataract surgery and vitrectomy in the right eye. Based on clinical and multimodal imaging findings, the patient was diagnosed with peripheral nonpigmented RPE adenoma and RP. Over three months of follow-up, his visual acuity remained stable (FC), with normal intraocular pressure and maintained retinal attachment. Subsequent silicone oil removal was performed without complications. This case highlights a rare occurrence of nonpigmented RPE adenoma in association with RP. Given its phenotypic resemblance to choroidal melanoma, three critical insights emerge: 1) RPE adenoma should be considered in the differential diagnosis when RP patients develop atypical retinal masses, 2) Diagnostic confirmation requires histopathological verification through immunohistochemical (IHC) markers and 3) Multidisciplinary evaluation integrating clinical, imaging, and histopathological data is essential to prevent misdiagnosis. This dual pathology presentation expands our understanding of retinal tumor manifestations in hereditary retinal degenerations.