We report a case of Coats disease in a 9-year-old boy who had a profoundvisual deficit and increasing pain in his right eye. Funduscopic examinationrevealed a complex, exudative retinal detachment with a subretinal mass andperipheral retinal telangiectasis. B-scan ultrasonography revealed a heterogeneouslyechogenic subretinal mass with several highly reflective foci consistent withcalcification. Enucleation was performed and confirmed the diagnosis of Coatsdisease. Histopathological examination revealed the heretofore unreportedfinding of intraretinal calcification.
In 1908, George Coats1 described a clinicalentity characterized by telangiectasis, aneurysmal retinal vessels, and intraretinaland/or subretinal exudates in young males. In 1912, Leber2 reporteda similar condition with telangiectasis and multiple retinal aneurysms butwithout the massive subretinal exudation found in Coats’ series. In1956, Reese3 observed that patients with multiplemiliary aneurysms progressed to massive subretinal exudation and proposedthat Leber’s and Coats’ cases represented a continuum of a singlepathologic process.
A recent review has further classified the criteria for Coats diseaseas idiopathic retinal telangiectasis, intraretinal and/or subretinal exudation,and frequent exudative retinal detachment without retinal or vitreal traction.4 Coats disease may be manifested at any age but ismost often diagnosed between the ages of 5 and 11 years.4 Itis typically unilateral, and approximately three fourths of the affected patientsare male. The majority of patients have decreased vision, strabismus, or leukocoria.4
Retinoblastoma is the most common primary intraocular malignancy inchildhood and may be difficult to distinguish from Coats disease based onhistory and ophthalmologic examination. The presence of intraretinal calcificationwithin a retinal mass strongly supports the diagnosis of retinoblastoma.
Herein, we present the clinicopathologic correlation of a patient withCoats disease consisting of a complex, exudative retinal detachment and subretinalmass with retinal telangiectasis. Although the history and clinical examinationsupported the diagnosis of Coats disease, retinoblastoma could not be definitivelyexcluded because of the detection of apparent foci of intraretinal calcificationwith ultrasonography.
A 9-year-old boy arrived at the Bascom Palmer Eye Institute complainingof severe ocular pain in his right eye for 2 weeks and progressive visualloss during several months. His past medical history and family history wereunremarkable. There was no history of ocular trauma.
On examination, the patient’s best corrected visual acuity was2/200 in the right eye and 20/20 in the left eye. A relative afferent pupillarydefect was present in the right eye. Anterior segment examination was unremarkable.
Dilated funduscopic examination of the right eye revealed a complex,exudative retinal detachment associated with multiple telangiectasias in thetemporal retina. Extensive subretinal fluid and apparent foci of lipid depositionwere present (Figure 1). No holes, tears,breaks, epiretinal membrane, or proliferative vitreoretinopathy formationwas identified. Examination of the left eye revealed no evidence of vascularanomaly, retinal mass, or tumor. Ultrasonography revealed a heterogeneouslyechogenic mass as well as highly reflective signals consistent with intraretinalcalcification in the temporal periphery (Figure2).
RetCam (Massie Research LaboratoriesInc, Dublin, Calif) images of the right eye reveal exudative retinal detachmentwith extensive subretinal fluid and foci of calcification in the posteriorpole (A) and, in the temporal periphery, telangiectatic vessels visible onthe surface of a complex, exudative retinal detachment (B).
B-scan ultrasonography of the temporalperiphery reveals a heterogeneously echogenic mass (large arrow), total retinaldetachment (small arrows), and highly reflective foci consistent with intraretinalcalcification (arrowhead).
The clinical evaluation in this case was most consistent with long-standingCoats disease. However, retinoblastoma could not be definitively excludedgiven the detection of intraretinal calcification by ultrasonography. Aftera thorough discussion of the treatment options, the family elected to proceedwith enucleation.
The enucleation specimen was sent to the Florida Lions Ocular PathologyLaboratory for evaluation. Gross pathologic examination revealed a yellow-whitesubretinal mass in the temporal retina with large, tortuous vessels on itssurface (Figure 3). Total retinal detachmentwas present, extending from the ora serrata to the posterior pole with a largeaccumulation of subretinal fluid (Figure 3).
Gross pathologic examination of theenucleated eye demonstrates total exudative retinal detachment with subretinalfluid. A yellow-white mass is present in the temporal retina just posteriorto the ora serrata.
Microscopic examination revealed the classic histopathological componentsof Coats disease. A focus of retinal telangiectasis was identified along withcholesterol cleft formation and lipid-laden foamy macrophages (Figure 4). Moreover, features of long-standing Coats disease wererevealed, including cystic retinal degeneration, a marked amount of subretinalfibrosis, and nodular proliferation of the retinal pigment epithelium. A focusof osseous metaplasia was present within the fibrotic subretinal mass. Overlyingthe subretinal mass were several areas of intraretinal calcification (Figure 5). There was no evidence of retinoblastomaor tumor.
Histopathological examination withhematoxylin-eosin staining reveals the classical components of Coats disease.A, A focus of dilated retinal vessels (arrows) is identified in the peripheralretina (original magnification × 200). B, Prominent intraretinalcholesterol clefts with surrounding histiocytes are present (original magnification × 200).C, Macrophages with engulfed foamy material (arrows) are present in an intraretinaland subretinal location (original magnification × 400).
Histopathological examination revealssubretinal fibrosis, ossification, and intraretinal calcification. A, Hematoxylin-eosinstaining reveals a marked amount of nodular proliferation of the retinal pigmentepithelium and fibrocellular tissue in the subretinal space (arrows; originalmagnification × 100). Proteinaceous material is interposedbetween this tissue and the retinal pigment epithelium. B, Osseous metaplasiais present within the center of the fibrous, metaplastic retinal pigment epithelium(arrow; original magnification × 400). C, Von-Kossa stainingdemonstrates a focus of intraretinal calcification at the equator (originalmagnification × 200).
The histopathological findings in this case are consistent with long-standingCoats disease. It has previously been reported that chronic Coats diseasemay progress to total retinal detachment and the development of a subretinalfibro-osseous nodule. Moreover, calcification and osseous metaplasia may occurwithin a subretinal mass in Coats disease.5 Toour knowledge, this is the first report of intraretinal calcification in Coatsdisease. Intraretinal calcification classically occurs in retinoblastoma;however, it may also be detected in retinocytoma, tuberous sclerosis, andepiretinal membranes.
This case reinforces the importance of a complete ophthalmic history,examination, and ancillary tests to distinguish Coats disease from retinoblastomabecause intraretinal calcification may be present in Coats disease. Nearlyone third of patients with Coats disease are referred to ocular oncology specialistsfor presumptive retinoblastoma.4 DistinguishingCoats disease from retinoblastoma may be difficult given the overlap of symptomsin a pediatric population.6 Moreover, ophthalmologicalexamination alone is often insufficient to establish a diagnosis. Ultrasonographicand computed tomographic scans are frequently used to further evaluate theposterior pole for masses, retinal detachment, and calcification.
Early diagnosis and treatment are critical in Coats disease. Patientswith retinal telangiectasis and retinal exudates generally have good visualoutcomes with laser photocoagulation.5,7 Incases of Coats disease with retinal detachment, the visual outcomes are generallypoor. However, drainage of subretinal fluid, reattachment of the retina, andcryotherapy of retinal telangiectasis may halt the progression to neovascularglaucoma.8,9
Enucleation is performed in approximately 16% of patients with Coatsdisease.7 Enucleation is typically indicatedin blind, painful eyes secondary to neovascular glaucoma. Enucleation wasperformed in this case primarily because of profound visual deficit and painwith little potential for visual rehabilitation with surgical retinal reattachment.Moreover, the presence of intraretinal calcification limited our ability todefinitively exclude retinoblastoma.
In conclusion, we present a case of Coats disease with extensive retinalpigment epithelium hypertrophy, osseous metaplasia, and intraretinal calcification.This is the first report of intraretinal calcification in Coats disease, andit emphasizes the challenge of distinguishing advanced Coats disease fromretinoblastoma.
Correspondence: Dr Dubovy, Florida LionsOcular Pathology Laboratory, Bascom Palmer Eye Institute, University of MiamiSchool of Medicine, 900 NW 17th St, Miami, FL 33136 (email@example.com).
Financial Disclosure: None.
Miller DM, Benz MS, Murray TG, Dubovy SR. Intraretinal Calcification and Osseous Metaplasia in Coats Disease. Arch Ophthalmol. 2004;122(11):1710-1712. doi:10.1001/archopht.122.11.1710