Combined hamartoma of the retina and retinal pigment epithelium (RPE) is a presumed congenital and nonhereditary benign fundus lesion.1 This mass occurs primarily in the retina and can mimic choroidal nevus, melanoma, and even retinoblastoma. More important, this tumor is recognized as a component of neurofibromatosis type 2.1–3
Clinically, combined hamartoma appears as an ill-defined gray retinal mass with posterior features of tortuous and kinked retinal blood vessels and peripheral features of straightened, dragged vessels on traction. It is speculated that these features are the result of retinal traction from epiretinal gliosis.1,4 In 1973, Gass2 described a black or charcoal gray raised mass involving the RPE, retina, and overlying vitreous that extends in a fan-like projection. The authors also described hyperpigmented tissue at the level of the RPE, thickened gray-white retinal and preretinal tissue in the inner and middle part of the tumor, and contraction of the inner surface of the tumor with retinal vascular tortuosity. There was no evidence of RPE or choroidal abnormality at the lesion margin and no retinal detachment, hemorrhage, inflammation, exudation, or vitreous cells.2 The vascular pattern of this tumor is emphasized on fluorescein angiography with markedly tortuous and staining retinal blood vessels.1
In 2002, Ting et al.5 observed time-domain optical coherence tomography (OCT) of combined hamartoma with poorly defined retinal thickening, irregularity, and hyperreflectivity (backscatter). In 2005, Shields et al.6 reviewed time-domain OCT in 11 cases of combined hamartoma and found pre-retinal membrane, vitreoretinal traction, and retinal disorganization in each case. Recently, Arepalli et al.4 used spectral-domain enhanced depth imaging OCT (EDI-OCT) for evaluation of combined hamartoma in 8 cases and found highly refined, consistent features of a distinct epiretinal membrane with retinal striae and/or folds, termed “mini- and maxi-peaks,” leading to increased mean retinal thickness of 608 µm. Herein, we review a case of combined hamartoma of the retina and RPE with characteristic EDI-OCT features of mini- and maxi-peaks.
A 17-year-old asymptomatic boy was referred for “macular gliosis” in the left eye. The patient denied hearing or neurologic deficits or a history of neurofibromatosis. There was a family history of thyroid and breast carcinoma.
At presentation, best-corrected visual acuity was 20/20 in the right eye and 20/30 in the left eye. Intraocular pressure and anterior segment examination were unremarkable with no signs of Lisch nodules or posterior subcapsular cataract in either eye. The right fundus was normal.
The left fundus demonstrated a prominent, fibrous, gray-white epiretinal membrane along the superotemporal retinovascular arcade with superior dragging of the vessels and the foveal tissue (Figure 1). There was no subretinal fluid or choroidal neovascularization. Ultrasonography confirmed an echodense, ill-defined, non-calcified mass of 2.5-mm thickness.
Combined hamartoma of the retina and retinal pigment epithelium in the left eye demonstrating white epiretinal fibrous tissue along the superotemporal vessels, causing retinal vascular dragging and retinal striae.
EDI-OCT demonstrated horizontal macular dragging toward the optic disc (Figure 2) with surface feature of multifocal “sawtooth” mini-peaks of vertical traction. In other vertical and horizontal spectral-domain OCT orientations, the maxi-peak pattern of combined hamartoma was noted with folded retina and attached epiretinal membrane. Some spectral-domain OCT cuts demonstrated both the mini-peak and maxi-peak topography. The retinal layers were remarkably well preserved. These findings were consistent with combined hamartoma of the retina and RPE. Observation was recommended.
Spectral-domain enhanced depth imaging optical coherence tomography of combined hamartoma. (A) Horizontal cut through inferior margin of lesion near the optic disc, showing classic mini-peak sawtooth patterns, with vitreoretinal adhesion. (B) Vertical cut through temporal portion of lesion, showing vitreoretinal traction with mini-peak sawtooth pattern, and one focus of dense preretinal fibrosis with retinal folding. (C) Horizontal cut through midportion of lesion, demonstrating dense flat epiretinal fibrosis with maxi-peak retinal folding involving all retinal layers. (D) Vertical cut through midportion of lesion, demonstrating dense flat epiretinal fibrosis with maxi-peak retinal folding and deep shadowing. (E) Vertical cut at temporal edge of lesion, showing dense focus of epiretinal fibrosis with both mini-peak (inferior edge) and maxi-peak (midportion) changes with outer retinal edema.
The introduction of OCT into clinical practice has enabled better assessment of retinal anatomy, particularly with retinal tumors.4 Time-domain OCT allowed analysis of the cross-sectional anatomy of the retina; however, this technology has provided little information on deeper structures such as the choroid and sclera.7 Because spectral-domain OCT and EDI-OCT have become available, the individual retinal layers are better delineated.4,7–9 Both time-domain and spectral-domain OCT have documented combined hamartoma with dense epiretinal membrane and with horizontal and vertical vitreoretinal traction at the site of the lesion. Specific information regarding the impact of the vitreoretinal traction is best depicted on EDI-OCT.4–10
In 2014, Shields et al.7 and Arepalli et al.4 illustrated specific features regarding the surface topography and deep anatomic changes of combined hamartoma using EDI-OCT.4,9 It is known that combined hamartoma displays epiretinal traction classified as tangential (horizontal dragging) or anteroposterior (vertical elevation).11 In their analyses,4,7 the tumor surface configuration was classified as mini- or maxi-peaks. Mini-peaks represented minute inward points of vitreoretinal traction causing acutely angled peaking of the retina into the vitreous gel in a sawtooth pattern, typically without outer retinal disturbances. Maxi-peaks represented large, broad areas of vitreoretinal traction with full-thickness retinal folding of both superficial and deep retinal tissues.4,7 In this case, both mini- and maxi-peaks were visualized on EDI-OCT (Figure 2).
Arepalli et al.4 explored specific features of EDI-OCT in 11 cases of combined hamartoma. They found prominent vitreoretinal traction in all cases, manifesting a sawtooth mini-peak pattern involving inner retina (n = 5) and folded maxi-peak pattern involving full-thickness retina (n = 6), and some cases with both patterns (n = 3). Of the five cases with mini-peak appearance, three showed acute (range: 45° to 90°) peak angle and two showed a hyperacute peak (< 45°).4 Additionally, they noted irregularities in all retinal layers from the nerve fiber layer to the photo-receptor layer. From this analysis, they concluded that combined hamartoma appeared to be predominantly an abnormality of the vitreoretinal interface rather than an intrinsic retinal or RPE tumor.4
Combined hamartoma of the retina and RPE shows characteristic features on EDI-OCT, including prominent epiretinal membrane with vitreoretinal traction forming a combination of mini- or maxi-peak appearance. These imaging features can assist in confirming the diagnosis and ruling out simulating conditions such as choroidal nevus or melanoma, as in our case. EDI-OCT has provided information that has assisted in our understanding of this condition.
- Shields JA, Shields CL. Combined hamartoma of the retina and retinal pigment epithelium. In: Shields JA, Shields CL, eds. Intraocular Tumors: An Atlas and Textbook, 2nd ed. Philadelphia: Lippincott, Williams, & Wilkins; 2008:450–452.
- Gass JDM. An unusual hamartoma of the pigment epithelium and retina simulating choroidal melanoma and retinoblastoma. Trans Am Ophthalmol Soc. 1973;71:171–183.
- Blumenthal EZ, Papmichael G, Merin S. Combined hamartoma of retina and retinal pigment epithelium: a bilateral presentation. Retina. 1998;18:557–559. doi:10.1097/00006982-199806000-00013 [CrossRef]
- Arepalli S, Pellegrini M, Ferenczy SR, Shields CL. Combined hamartoma of the retina and retinal pigment epithelium: findings on enhanced depth imaging optical coherence tomography in eight eyes. Retina. 2014;34:2202–2207. doi:10.1097/IAE.0000000000000220 [CrossRef]
- Ting TD, McCuen BW II, Fekrat S. Combined hamartoma of the retina and retinal pigment epithelium: optical coherence tomography. Retina. 2002;22:98–101. doi:10.1097/00006982-200202000-00016 [CrossRef]
- Shields CL, Materin MA, Shields JA. Review of optical coherence tomography for intraocular tumors. Curr Opin Ophthalmol. 2005;16:141–154. doi:10.1097/01.icu.0000158258.01681.40 [CrossRef]
- Shields CL, Pellegrini M, Ferenczy SR, Shields JA. Enhanced depth imaging optical coherence tomography of intraocular tumors: from placid to seasick to rock and rolling topography–the 2013 Francesco Orzalesi Lecture. Retina. 2014;34:1495–1512. doi:10.1097/IAE.0000000000000288 [CrossRef]
- Spaide RF, Koizumi H, Pozzoni MC. Enhanced depth imaging spectral-domain optical coherence tomography. Am J Ophthalmol. 2008;146:496–500. doi:10.1016/j.ajo.2008.05.032 [CrossRef]
- Shah S, Kaliki S, Shields CL, Ferenczy SR, Harmon SA, Shields JA. Enhanced depth imaging optical coherence tomography of choroidal nevus in 104 cases. Ophthalmology. 2012;119:1066–1072. doi:10.1016/j.ophtha.2011.11.001 [CrossRef]
- Shields CL, Mashayeki A, Dai VV, Materin MA, Shields JA. Optical coherence tomographic findings of combined hamartoma of the retina and retinal pigment epithelium in 11 patients. Arch Ophthalmol. 2005;123:1746–1750. doi:10.1001/archopht.123.12.1746 [CrossRef]
- Shields CL, Thangappan A, Hartzell K, Valente P, Pirondini C, Shields JA. Combined hamartoma of the retina and retinal pigment epithelium in 77 consecutive patients: visual outcome based on macular versus extramacular tumor location. Ophthalmology. 2008;115:2246–2252. doi:10.1016/j.ophtha.2008.08.008 [CrossRef]