Objective: To describe the clinical features of solitary congenital hypertrophy of the retinal pigment epithelium (CHRPE) and to determine the frequency of enlargement of this lesion
Design: Retrospective, observational, noncomparative case series.
Participants: Three hundred thirty consecutive patients with solitary CHRPE.
Main outcome measures: The 3 main outcome measures included flat lesion enlargement, intralesional lacunae enlargement, and development of an elevated nodule within the lesion. The clinical features at the time of presentation were analyzed for their impact on the main outcomes using a series of Cox proportional hazards regressions.
Results: The most common referring diagnosis included choroidal nevus (26%), choroidal melanoma (15%), CHRPE (9%), and unspecified lesion (48%). The median age at diagnosis was 45 years (range, 1-80 years), and there were no patients with familial adenomatous polyposis or related colon cancer, although a history of cancer was noted in 8% of patients, most commonly breast cancer (3%). The lesion most frequently was located inferotemporally (31%) and at the equatorial region (45%). Rarely, it was located in the macula (1%) or peripapillary region (1%). The median largest basal diameter was 4.5 mm, and the lesion was flat in all cases except in 5 (1.5%), in which there was an intralesional lesion nodule. The lesion was pigmented in 88% of cases and nonpigmented in 12%. Lacunae were noted in 43% of the pigmented CHRPE, and the lacunae showed gradual enlargement in 32%. Factors related to lacunae enlargement included number and relative size of lacunae. Flat enlargement of the lesion was documented in 46% of patients with comparative photographic follow-up and in 83% of those followed up for more than 3 years. The median rate of enlargement was 10 micro m per month. The most important factor associated with flat lesion enlargement was relative size of the lacunae within CHRPE. There were no cases of CHRPE in which a nodule developed while the patient was being followed up. Of the 5 lesions that had a nodule, progressive enlargement of the nodule was found in 3.
Conclusions: Congenital hypertrophy of the retinal pigment epithelium generally has been regarded as a benign, stable lesion, but subtle, flat enlargement was noted in most patients (83%) followed up for 3 or more years using meticulous photographic comparison. Flat enlargement of the lesion appeared to be related to percentage of the mass occupied by lacunae.