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A

B

Figure 49-4.  Retinoblastoma. A, before and B, after intra-arterial chemotherapy.

Bibliography

Kivela T: The epidemiological challenge of the most frequent eye cancer: retinoblastoma, an issue of birth and death, Br J Ophthalmol 93:1129–1131, 2009.

Ramasubramanian A, Shields CL, editors: Retinoblastoma, New Delhi, India, 2012, Jaypee Brothers Medical Publishers. Shields JA, Shields CL: Intraocular tumors: a text and atlas, Philadelphia, 1992, W.B. Saunders. 305–392.

Shields JA, Shields CL: Intraocular tumors. An atlas and textbook, ed 2, Philadelphia, 2008, Lippincott Williams and Wilkins. Shields CL, Fulco EM, Arias JD, et al.: Retinoblastoma frontiers with intravenous, intra-arterial, periocular and intravitreal

chemotherapy, Eye 27:253–264, 2013.

Shields CL, Schoenfeld E, Kocher K, et al.: Lesions simulating retinoblastoma (pseudoretinoblastoma) in 604 cases, Ophthalmology 120:311–316, 2013.

1.What is the main differential diagnosis of a relatively flat pigmented fundus lesion?

1.Choroidal nevus (Fig. 50-1)

2.Congenital hypertrophy of the retinal pigment epithelium (CHRPE) (Fig. 50-2)

3.Combined hamartoma

2.What ophthalmoscopic features help to differentiate choroidal nevus, CHRPE, and combined hamartoma?

Choroidal nevus is generally a slate-gray lesion with a slightly ill-defined border. Drusen may be present on the surface of the lesion. CHRPE is usually black, has a sharply demarcated border, and may have depigmented lacunae through which the underlying choroid can be visualized. Combined hamartoma shows vitreoretinal traction that is not seen with the other two conditions.

3.Do both choroidal nevus and CHRPE have malignant potential?

Although both lesions are benign and usually stationary, nevus can give rise to melanoma and most melanomas probably arise from a preexisting nevus. CHRPE was once believed to be stationary with no malignant potential. However, it has recently been recognized to show enlargement in diameter in

Figure 50-1.  Typical choroidal nevus adjacent to the optic disc.

Figure 50-2.  Congenital hypertrophy of the retinal pigment epithelium.

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394  OPHTHALMOLOGY SECRETS IN COLOR

80% of cases and to rarely become elevated and evolve into adenocarcinoma of the retinal pigment epithelium.

4.What is the main differential diagnosis of an elevated pigmented fundus lesion?

1.Choroidal melanoma

2.Subretinal hemorrhage

3.Tumor of the retinal pigment epithelium

4.Bilateral diffuse uveal melanocytic proliferation

5.What ophthalmoscopic features help to differentiate a choroidal melanoma from a subretinal hemorrhage?

Choroidal melanoma usually is a rather homogeneous brown-to-black lesion with a smooth surface. Subretinal hemorrhage in the macular area (age-related macular degeneration) or in the peripheral fundus (peripheral disciform degeneration) initially has a reddish-blue color; because it undergoes resolution, it has a more heterogeneous color with areas of fresh red blood and older yellow blood.

6.What is the most practical ancillary test for differentiating choroidal melanoma from subretinal blood?

The most practical test is fluorescein angiography. Most melanomas show hyperfluorescence, and most hemorrhages are hypofluorescent.

7.What is the significance of a mushroom-shaped fundus lesion?

A mushroom-shaped fundus lesion is strongly suggestive of choroidal melanoma (Fig. 50-3). Even when the mushroom-shaped lesion is nonpigmented, melanoma is still the most likely diagnosis. It is very unusual for other fundus lesions to assume a mushroom shape.

8.What is the best way to diagnose choroidal melanoma?

The best way is the use of binocular indirect ophthalmoscopy by an experienced ophthalmologist who is familiar with the characteristic features of choroidal melanoma and other lesions that simulate choroidal melanoma. Most melanomas can be readily diagnosed by indirect ophthalmoscopy alone. However, ancillary studies such as fluorescein angiography and ultrasonography are also quite reliable.

9.When the diagnosis is uncertain after ophthalmoscopy, what are the four most helpful ancillary tests in the diagnosis of uveal melanoma?

1.Transillumination

2.Fluorescein angiography

3.Ultrasonography

4.Fine-needle aspiration biopsy

Most melanomas cast a shadow with transillumination, are hyperfluorescent with angiography, and show low internal reflectivity with ultrasonography. Most simulating lesions show different patterns with these modalities. Fine-needle aspiration biopsy is perhaps the most reliable method, but it is an invasive procedure that requires a skilled and experienced physician.

10.What clinical signs suggest that a benign choroidal nevus is likely to grow and eventually evolve into a malignant choroidal melanoma?

Elevation of the lesion, orange pigment on the surface of the lesion, secondary retinal detachment, proximity of the lesion to the optic disc, and presence of visual symptoms.

KEY POINTS: RISK FACTORS FOR GROWTH OF CHOROID NEVUS

1. Thickness greater than 2 mm

2. Associated retinal detachment (subretinal Fluid)

3.Visual Symptoms due to the tumor

4.Orange pigment

5.Margin within 3 mm of the optic disc

The mnemonic “To Find Small Ocular Melanoma” is used clinically to estimate the possibility of growth of the nevus.

CHAPTER 50  PIGMENTED LESIONS OF THE OCULAR FUNDUS  395

11.What clinical signs suggest that a small, suspicious pigmented fundus lesion may eventually metastasize?

1.Elevation of the lesion >2 mm

2.Proximity to the optic disc

3.Visual symptoms

4.Documentation of growth

It is important that documented growth is a risk factor for metastasis. Therefore, if other risk factors for growth and metastasis are present, the ophthalmologist should consider treatment without waiting for growth.

12.What congenital ocular conditions are associated with a higher incidence of uveal melanoma?

Congenital ocular melanocytosis and oculodermal melanocytosis (nevus of Ota) are the main conditions, perhaps because of the excessive melanocytes in their uveal tract, that predispose to a greater chance of developing uveal melanoma.

13.Does uveal melanoma have a predilection for gender, age, or race?

Uveal melanoma has no significant predilection for gender. It generally occurs in patients between

40and 70 years of age and is relatively uncommon in patients younger than age 20. It has a definite predilection for Caucasians; only 1% to 2% of cases occur in African Americans and Asians.

14.What external ocular signs suggest the possibility of an underlying ciliary body or peripheral choroidal melanoma?

1.One or more dilated, tortuous episcleral blood vessels in the ciliary body region (sentinel vessels; Fig. 50-4).

2.A black focus of pigment on the sclera, indicative of extraocular extension of the melanoma.

Figure 50-3.  Mushroom-shaped choroidal melanoma.

Figure 50-4.  Sentinel vessel over a ciliary body melanoma.

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