Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem disorder with highly variable findings. The prevalence has been estimated about one in 100,000.1 Retinal astrocytic hamartomas have been documented in up to 87% of individuals with TSC.2 Although their clinical appearance has been extensively described, the value of optical coherence tomography (OCT) in the evaluation of astrocytic hamartomas has been less well-documented. By spectral-domain OCT (SD-OCT), astrocytic hamartoma consists of a solid intraretinal mass continuous with the inner retina, often with hyperreflective intralesional globules, cystic spaces, and interdigitation with the overlying vitreous.3 Here, a patient with astrocytic hamartoma associated with TSC is presented in which multimodal imaging included OCT angiography (OCTA).
An 11-year-old female was referred to the Bascom Palmer Ocular Oncology Service for evaluation of a white retinal mass in the left eye. Best-corrected visual acuity was 20/20 in the right eye and 20/25 in the left eye. Intraocular pressures were normal. External examination was significant for subtle, previously unrecognized pigmented skin lesions located on the right lower lid (Figure 1A) and right upper chest (Figure 1B), consistent with shagreen patches. Small cutaneous lesions on the cheeks and nose had been assumed by the family to represent early acne but were consistent with subtle adenoma sebaceum (Figure 1C). Ophthalmic examination revealed a whitish-gray intraretinal lesion inferior to the optic disc in the left eye, as well as similar smaller lesions identified in the temporal periphery of the right eye, and in the superior macula and temporal periphery of the left eye (Figure 2). The lesion inferior to the disc in the left eye was evaluated using Cirrus 5000 OCT with AngioPlex OCTA (Zeiss, Oberkochen, Germany) and revealed prominent intrinsic vascularity without obvious feeder vessels (Figures 3A and 3B). There was a history of intellectual delay but no seizures. Genetic testing confirmed a germline mutation in the TSC1 gene.
Cutaneous findings consistent with tuberous sclerosis complex. (A) Subtle pigmented lesion along the right lower lid consistent with shagreen patch. (B) Subtle pigmented lesion on right upper chest consistent with shagreen patch. (C) Subtle, acne-like skin lesions on cheeks and nose consistent with adenoma sebaceum.
Spectral-domain optical coherence tomography, left eye. A small, subtle, whitish-gray retinal lesion in the superior macula (upper white arrow) appears solid and contiguous with the inner retinal layers. A similar but larger retinal lesion located at the inferior margin of the optic disc (lower white arrow) also appears to arise from inner retinal layers and has replaced much of the outer retinal layers.
Optical coherence tomography angiography, left eye. In the superficial slab (A) and the deep slab (B), the retinal lesion inferior to the optic disc shows intrinsic vascularity but no feeder vessel.
To our knowledge, this is the first description of OCTA findings in an astrocytic hamartoma associated with tuberous sclerosis complex. Two recent publications reported OCTA findings of isolated astrocytic hamartomas. Using the RTVue XR Avanti with Angiovue (Optovue, Fremont, CA), Yung et al.4 reported a prominent feeder vessel within the deep capillary plexus, but we did not see that feature in our patient. Using the Optovue device, Despreaux et al.5 described an astrocytic hamartoma in which there was a diffuse vascular network within both the deep and superficial capillary plexi, as well as overlying vitreous abnormalities, which we did not see in our case.
It is interesting that the feeder vessels and vascular networks described in previous cases were not noted here. The reason for this is unknown, but there may be multiple contributing factors. First, the lesions in the present case are relatively small. The larger lesion, just inferior to the optic disc, is approximately one-half disc area in size. In contrast, the lesions reported elsewhere were substantially larger, each greater than one disc area. Perhaps the intrinsic vessels are easier to visualize in larger lesions. Alternatively, it may be hypothesized that smaller hamartomas may represent an earlier stage in the disease process, and that the intrinsic vascularity increases in more mature, larger lesions. Traditional fluorescein angiography might provide additional information, but it was decided not to perform this testing on this young patient.
Second, the present case was imaged with the Zeiss device with commercially available software. In contrast, the previous cases were imaged with the Optovue device. Additionally, one of the previous cases underwent subsequent image manipulation with separate software.4 Perhaps the difference in methodology affects the ability to demonstrate the intrinsic vessels.
Our findings identify intrinsic vascularity within an intraretinal lesion arising within the inner retinal layers as a key OCTA feature of astrocytic hamartoma and demonstrate the utility of OCT for detecting subtle astrocytic hamartomas. Further research comparing sporadic astrocytic hamartomas and those associated with tuberous sclerosis complex may provide further insights into the pathogenesis of these lesions.
- Hong CH, Tu HP, Lin JR, Lee CH. An estimation of the incidence of tuberous sclerosis complex in a nationwide retrospective cohort study (1997–2010). Br J Dermatol. 2016;174(6):1282–1289. doi:10.1111/bjd.14415 [CrossRef]
- Kiribuchi K, Uchida Y, Fukuyama Y, Maruyama H. High incidence of fundus hamartomas and clinical significance of a fundus score in tuberous sclerosis. Brain Dev. 1986;8(5):509–517. doi:10.1016/S0387-7604(86)80096-1 [CrossRef]
- Schwartz SG, Harbour JW. Spectral-domain optical coherence tomography of presumed solitary circumscribed retinal astrocytic proliferation versus astrocytic hamartoma. Ophthalmic Surg Lasers Imaging Retina. 2015;46(5):586–588. doi:10.3928/23258160-20150521-13 [CrossRef]
- Yung M, Iafe N, Sarraf D. Optical coherence tomography angiography of a retinal astrocytic hamartoma. Can J Ophthalmol. 2016;51(2):e62–64. doi:10.1016/j.jcjo.2015.11.005 [CrossRef]
- Despreaux R, Mrejen S, Quentel G, Cohen SY. En face optical coherence tomography (OCT) and OCT angiography findings in retinal astrocytic hamartomas. Retin Cases Brief Rep. 2016Aug9 [Epub ahead of print]. doi:10.1097/ICB.0000000000000374 [CrossRef]