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Adenoma of the retinal pigment epithelium: a report of 3 cases.

OBJECTIVE
To report the clinical manifestations and pathologic features of adenoma of the retinal pigment epithelium (RPE).


DESIGN
Retrospective study.


PARTICIPANTS
Three patients with an initial clinical diagnosis of choroidal melanoma.


METHODS
Routine eye examinations, including visual acuity, intraocular pressure, slit-lamp examination, and ophthalmoscopy, were performed. Auxiliary examinations included fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA), B-scan ultrasonography, colour Doppler imaging (CDI), and MRI. Endoresection of the tumours was performed, and the specimens underwent pathological examination.


RESULTS
The tumours were of yellow-pink or brown colour and all located in the right eye. On FFA and ICGA, the tumours demonstrated hypofluorescence in the early phase and hyperfluorescence with prominent leakage in the late phase. CDI showed arterial blood signals in the tumour, and MRI showed hyperintensity in the T1-weighted image and hypointensity in the T2-weighted image. On pathological examination all the tumours were positive with periodic acid-Schiff, S-100, neurone-specific enolase, synaptophysin, epithelial membrane antigen, and vimentin staining but negative with melanoma-specific antigen HMB45, and cytokeratin. After 3 years of follow-up, there was no tumour recurrence and the retinas remained attached.


CONCLUSIONS
RPE-derived adenoma is difficult to diagnose clinically. In most cases, pathological confirmation is needed. Local resection is a favorable alternative treatment for some patients.