Unsuspected and misdiagnosed ciliary body and choroidal melanoma after enucleation and evisceration: review of cases in the Ottawa-Gatineau region from 1996-2012

Abstract

 

Purpose

 

There is little in the recent literature on the topic of clinically unsuspected and misdiagnosed ciliary body and choroidal melanomas with a calculation of the frequency of these events for a set geographical area. We present 2 cases unexpectedly diagnosed with a melanoma of the ciliary body and choroid after enucleation and evisceration, respectively, and 2 cases of clinically misdiagnosed ciliary body and choroidal melanoma. As the only ophthalmic pathology laboratory in our region serving a population of 1,236,300, we determined the rate of these outcomes over a period of 16 years.

 

Methods

 

We carried out a retrospective single centred, population based case review in the Ottawa-Gatineau region. We reviewed 3,320 total cases, of which 98 were ciliary body and choroidal melanomas. Four cases were included in the study group. We calculated the frequency of clinically unsuspected melanoma of the ciliary body and choroid in enucleated and eviscerated eyes and of clinically misdiagnosed melanoma of the ciliary body and choroid in enucleated eyes in our region. We also determined the rate of uveal melanoma undergoing enucleation in our region by calculating the annual population and the mean number of cases within this area over a 16-year-span.

 

Results

 

Out of 98 diagnoses of ciliary body and choroidal melanoma, we identified 2 cases where the diagnosis was clinically unsuspected. We also identified 2 cases clinically misdiagnosed as a ciliary body or choroidal melanoma, with one of these being a non-neoplastic lesion. In our region, 2.0% of ciliary body and choroidal melanomas were clinically unsuspected and 2.0% of clinically diagnosed ciliary body and choroidal melanomas were misdiagnosed. We also calculated the rate of uveal melanoma undergoing enucleation in our region of 5.4 cases/1,000,000 population/year.

 

Conclusions

 

We present the first and only single centred, population based data on the rates of unsuspected and misdiagnosed ciliary body and choroidal melanoma in the current era of modern diagnostic imaging. Unsuspected melanoma of the ciliary body or choroid is a rare occurrence, with a rate significantly lower than previously published. The rate of clinically misdiagnosed ciliary body or choroidal melanoma at our centre is within the range of recent reports of this encounter.