Bilateral diffuse retinal pigment epithelium proliferation induced by choroidal inflammation: A case report.

Proliferation of retinal pigment epithelium (RPE) is typically observed in limited ocular disorders, in connection with the local mechanism of RPE proliferation-mediated wound repair. Bilateral and diffuse type RPE proliferation is considered to be associated with paraneoplastic syndromes, such as a bilateral diffuse uveal melanocytic proliferation. However, other reported diseases that induce bilateral diffuse RPE proliferation are quite rare, especially for patients who are considered to have a non-malignant status. The bilateral eyes of a 47-year-old woman with bilateral ocular inflammation, presented united multiple small to medium white retinal lesions during the disease progress. Optical coherence tomography showed scattered serous retinal detachments, choroidal folds, choroidal thickening and diffuse RPE proliferation. As autofluorescence and angiography showed a "giraffe pattern", bilateral diffuse uveal melanocytic proliferation was suspected. However, systemic investigations identified no malignancy. In consideration of the above findings, choroidal inflammation was thought to be the major cause of this condition. The patient was administered intensive systemic steroids. Over the next 2 months, the amount of steroid was tapered off. After administration, the bilateral diffuse RPE proliferation settled down. During the 2-year follow-up, there was no recurrence of ocular inflammation and diffuse RPE proliferation, or any other malignancy found. This finding demonstrates that bilateral diffuse RPE proliferation can be generated as a secondary phenomenon of choroidal inflammation in patients with a non-malignant status.