Indocyanine green angiography of optic nerve head melanocytoma

Melanocytoma of the optic disk: A review

Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina or choroid. Historically, this tumor was often confused with malignant melanoma both clinically and histopathologically. Today, however, it is generally recognized by its typical clinical features that differ from most melanomas and erroneous enucleation is rarely done. Histopathologically, melanocytoma is composed of intensely pigmented round to oval nevus cells with benign features. Although traditionally believed to be a relatively stationary lesion, it is now known to exhibit minor enlargement in 10--15% of cases and can cause minor visual loss by a variety of mechanisms. In rare instance, it can induce severe visual loss due to spontaneous necrosis of the lesion or compressive optic neuropathy. More importantly, it can exhibit malignant transformation into melanoma in 1--2% of cases. Ophthalmologists should be familiar with melanocytoma of the optic disk and affected patients should be followed periodically.

Melanocytoma of the optic disk: a review

Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina or choroid. Historically, this tumor was often confused with malignant melanoma both clinically and histopathologically. Today, however, it is generally recognized by its typical clinical features that differ from most melanomas and erroneous enucleation is rarely done. Histopathologically, melanocytoma is composed of intensely pigmented round to oval nevus cells with benign features. Although traditionally believed to be a relatively stationary lesion, it is now known to exhibit minor enlargement in 10-15% of cases and can cause minor visual loss by a variety of mechanisms. In rare instance, it can induce severe visual loss due to spontaneous necrosis of the lesion or compressive optic neuropathy. More importantly, it can exhibit malignant transformation into melanoma in 1-2% of cases. Ophthalmologists should be familiar with melanocytoma of the optic disk and affected patients should be followed periodically.

Mélanocytome de la papille : à propos de trois observations

PURPOSE

Melanocytoma is a rare benign tumor that usually occurs as a pigmented lesion in the optic nerve head. It seems to be more frequently encountered in the Black population. We report three cases of melanocytoma observed in Martinique, where 90% of the population is of African origin.

OBSERVATIONS

The first and second cases were found on routine ophthalmic examination. These patients had a heavily pigmented lesion that obscured part or all of the optic disc with slight extension into the adjacent nerve fiber layer of the retina. The tumor's margins were finely fibrillated. Fluorescein angiography demonstrated a homogenous hypofluorescent black tumor obscuring the optic disc vessels, with no tumor vessels visible. There were no juxtapapillary choroid vascular abnormalities. The third case was discovered on visual field examination. This melanocytoma was accompanied by papillary edema.

CONCLUSION

Only three cases of melanocytoma have been noted from 1994 to 2004 in 150,000 Caribbean patients examined in the University Hospital Center of Fort de France. The rarity of melanoma and the predisposition to melanocytoma are important epidemiologic factors in the etiologic search for pigmented tumor within the Black population. Yearly fundus examination is useful for monitoring growth and detecting malignant transformation.

[Diagnostic difficulties in pigmented tumor of the optic nerve head. A case report]

Melanocytoma of the optic disc is a benign pigmented tumor located on the optic nerve head. Most cases are visually asymptomatic but in rare cases it can cause visual loss, which does not necessarily involve malignant transformation. We present a case of melanocytoma in a 49-year-old woman who presented with decreased vision in her left eye. The pigmented mass was in close continuity with the juxtapapillary adjacent choroid. Fluorescein angiography demonstrated hypofluorescence with adjacent disc edema. Ultrasonography disclosed a high internal reflectivity mass in the optic nerve head without retrobulbar extension. Magnetic resonance imaging (T1 weighted images) disclosed a hyperintense signal on the optic nerve head. The tumor was stationary for 20 months. This report emphasizes problems differentiating a melanocytoma from malignant melanoma of the optic nerve. Unusual features of melanocytoma (superior nasal location in the optic disc with an adjacent choroidal component, a decrease in visual acuity and disc edema surrounding the tumor) are discussed. Visual loss can be induced by optic neuropathy or retinal vascular obstruction. Melanocytomas grow very slowly over several years or remains stable, in contrast to malignant melanoma. In suspicious cases, close follow-up with serial fundus photographs is essential, although malignant transformation is exceptional.

Indocyanine green angiography in chorioretinal diseases: indications and interpretation: an evidence-based update

TOPIC/PURPOSE: To assess the clinical usefulness and relevance of indocyanine green angiography (ICG) in the investigation of chorioretinal disorders and assess specifically in what conditions it may add useful information to that obtained using standard fluorescein angiography.

CLINICAL RELEVANCE

Many publications on ICG have appeared in recent years touting its use in ophthalmology. These publications have led to increasing use of this technique and to its application in numerous retinal diseases in which the fluorescein angiographic findings have been thoroughly described.

METHODS/LITERATURE REVIEWED

During this systematic literature review, we identified and reviewed a total of 376 articles, from among which we selected 92 that we considered most relevant to our purpose of evaluating published evidence as to the efficacy of ICG. We excluded many articles with weak study designs and those that simply duplicated previously published information. Our literature search used PubMed and was confined to articles in English or that included an English abstract.

RESULTS

Our systematic review suggests that ICG has relatively few specific indications for use as justified by previously published peer-reviewed studies. In keeping with the requirements for this Journal's evidence-based articles, we have divided our clinical recommendations for the use of ICG into three categories: (A) strongly recommended and supported by strong evidence; (B) recommended with moderately strong supporting evidence; (C) not recommended at present because supported only by anecdotal or group consensus evidence. We highly recommended ICG for (1) identification of polypoidal choroidal vasculopathy, (2) occult choroidal neovascularization, (3) neovascularization associated with pigment epithelial detachments, and (4) recurrent choroidal neovascular membranes. These are all conditions in which ICG contributes to the identification of lesions that may be treatable. We recommend ICG with some enthusiasm for identifying feeder vessels in age-related macular degeneration, choroidal neovascular membranes, chronic central serous retinopathy, multiple evanescent white dot syndrome, vasculitis, acute multifocal placoid pigment epitheliopathy, Vogt-Koyanagi-Harada syndrome, macular lesions associated with angioid streaks, and birdshot retinopathy. In all these conditions, ICG may help establish a diagnosis and provide some useful guidance for therapy. At present, we do not recommend ICG for scleritis and posterior scleritis, drusen differentiation, Behçet's disease, or sarcoidosis, because it has not been demonstrated to add useful clinical information.

CONCLUSIONS

ICG, although now a well established technique, has clear advantage over fluorescein angiography in relatively few chorioretinal disorders. It has, however, contributed to the understanding of pathologic processes in many ocular diseases. As yet, no published randomized controlled clinical trials show any benefit to the use of ICG in the management of any specific ocular disease.