Peripheral Hemorrhagic Chorioretinopathy: Differentiating Features from Choroidal Melanoma.

Introduction: Peripheral exudative hemorrhagic chorioretinopathy (PEHCR) is one of the leading mimickers of choroidal melanoma because of overlapping features with choroidal melanoma that make the distinction between these two entities difficult.

Methods: To identify nonoverlapping diagnostic features between PEHCR and choroidal melanoma, a retrospective study of 80 patients (80 eyes); 40 patients (40 eyes) with PEHCR; and 40 patients (40 eyes) with choroidal melanoma was conducted. Ophthalmoscopic and imaging features of PEHCR and choroidal melanoma were compared. Sensitivity and specificity for identifying PEHCR and choroidal melanoma were calculated. Youden's J statistic was assessed for each diagnostic feature.

Results: The most frequent clinical features of PEHCR were presence of druse (100%), hemorrhagic PED (93%), dome-shaped mass (B-scan) (90%), and subretinal/intraretinal hemorrhage (78%). Statistical analysis confirmed high sensitivity of hemorrhagic PED (0.93; 95% CI 0.80-0.98) and high specificity of clot retraction cleft, presence of lipid exudation, and bilaterality (1.00; 95% CI 0.91-1.00) as diagnostic features of PEHCR. Statistical analysis revealed presence of subretinal fluid 0.80 (95% CI 0.54-0.91) was most sensitive and presence of orange pigment, mushroom shape on B-scan, ciliary body extension, and choroidal excavation were most specific (1.00; 95% CI 0.91-1.00) for choroidal melanoma. Nonoverlapping diagnostic features of PEHCR were hemorrhagic PED, clot retraction cleft, presence of lipid exudation, and bilaterality. All PEHCR patients (100%) had at least one of these nonoverlapping diagnostic features. Nonoverlapping diagnostic features of choroidal melanoma were the presence of orange pigment, choroidal excavation, mushroom-shaped mass, and ciliary body extension (the latter 3 detected on B-scan). Youden's J statistic was highest for hemorrhagic PED and lowest for dome-shape appearance on B-scan (0.075).

Conclusion: PEHCR and choroidal melanoma can be differentiated by identifying diagnostic features that are exclusive to each entity. The presence of hemorrhagic PED strongly supports a diagnosis of PEHCR. B-scan ultrasonography is required to detect a mushroom-shaped mass, choroidal excavation, or ciliary body extension to exclude underlying choroidal melanoma.