Comment re: Unilateral solitary choroidal granuloma as presenting sign of secondary syphilis

Abstract

Dear Editor: We read with interest the paper by van der Vaart and colleagues [1] entitled “Unilateral solitary choroidal granuloma as presenting sign of secondary syphilis,” and were struck by the similarity of the color fundus images of the two presented cases to the findings in Acute Syphilitic Posterior Placoid Chorioretinopathy (ASPPC) [2]. Our recently reported case series and comprehensive review of the literature concluded that ASPPC lesions, like the two presented, tend to be yellow-white, flat, round or oval-shaped, and often involving the macula [2]. While detailed descriptions of additional imaging studies were not presented by van der Vaart and associates, we have found ancillary imaging to be quite useful in the diagnosis of ASPPC [2]. Fluorescein angiography, for example, tends to show early hypofluorescence with progressive late hyperfluorescence, often with an irregular or ‘leopard skin’ pattern. Indocyanine green typically shows hypofluorescence corresponding to the macular lesion in both the early and late phases, although late hyperfluorescence can be observed as well. In the acute setting, Spectral Domain-Ocular Coherence Tomography (SD-OCT) tends to show some degree of disruption of the outer retinal hyper-reflective bands associated with the external limiting membrane, the photoreceptors, and/or the photoreceptorretinal pigment epithelium (RPE) junction. Irregular nodularity of the photoreceptor-RPE junction can also be observed. Lastly, enhanced depth imaging (EDI) OCT and B-scan ultrasonography show no thickening of the choroid or scleral in ASPPC, and effectively rule out choroiditis and scleritis as a cause of the lesion. All of these changes typically normalize completely following treatment with neurosyphilis doses of intravenous penicillin for 10 to 14 days. Given the diameter of the lesions presented by van der Vaart and colleagues, one would expect the choroid to be thickened if choroiditis were, in fact, the underlying cause. Perhaps this is what the authors intended when they wrote that the “granulomatous choroidal lesions were singular and rounded in appearance, with height noted also on OCT.” A more detailed description of findings noted on imaging studies performed by the authors would be of interest. It is noteworthy that both of the patients reported by van der Vaart and associates [1] did quite well following a 2week treatment with intravenous penicillin, despite the fact that one was infected by the human immunodeficiency virus (HIV; the status of the second patient was not reported). While a number of case reports and small clinic-based series have suggested that HIV co-infection can worsen the severity and/or outcome of ocular syphilis, our experience and The authors have no financial interest in any aspect of this manuscript and have full control of all primary data.