Melanocytoma (magnocellular nevus) of the ciliary body: report of 10 cases and review of the literature

doi:10.1016/S0161-6420(99)00151-7

Ophthalmology

Volume 107, Issue 4, April 2000, Pages 795-800

Presented in part at the annual meeting of the Association for Research in Vision and Ophthalmology, Ft. Lauderdale, Florida, May 1995.

https://doi.org/10.1016/S0161-6420(99)00151-7 Get rights and content

Abstract

Purpose

To describe the characteristics of melanocytoma (magnocellular nevus) of the ciliary body, an unusual melanocytic tumor.

Design

Retrospective, clinicopathologic case series.

Methods

Ten melanocytomas of the ciliary body were examined histopathologically. Five tumors were also examined by transmission electron microscopy. The clinical histories were abstracted from the patients’ medical records. We compared the clinical, histopathologic, and ultrastructural findings of our 10 cases with those previously reported in the literature.

Main outcome measures

To define clinical and histopathologic parameters of this rare tumor.

Results

A total of 40 cases were summarized, including our 10 and 30 previously reported cases. The mean age of the 40 cases was 47 years. Twenty-six patients were female (65%), fourteen were male (35%). No laterality was observed. Eighty percent of the patients were white and 10% were black. The most common clinical presentation was an asymptomatic dark spot involving the iris and ciliary body or the sclera. Involvement of chamber angle structures, with or without intrascleral extension, was observed in 85% (34 of 40 patients); but only 12% (2 of the 17 patients for whom information about intraocular pressure and local extension was available) had elevated preoperative intraocular pressure. By electron microscopy, two distinct cell types were observed.

Conclusions

Melanocytomas can usually be distinguished from other pigmented lesions of the ciliary body by histopathologic criteria, but may be difficult to differentiate before surgery from other pigmented ciliary body tumors, including malignant melanomas, adenomas, and adenocarcinomas of the pigmented ciliary epithelium. Most tumors can be managed conservatively by iridocyclectomy.

Section snippets

Materials and methods

We examined histopathologically 10 melanocytomas of the ciliary body from 10 patients. Nine of the 10 patients were treated at our institution and one was a consultation. Sections were cut at five μm, and the slides were stained with hematoxylin and eosin and the periodic-acid-Schiff methods. Sections were also bleached for 30 minutes using 0.25% potassium permanganate and counterstained with Mayer’s hematoxylin. Representative samples were submitted for conventional transmission electron

Results

The average age of the patients in our series at the time of surgery was 46.5 years (range, 7–85 years). There were seven women and three men. Eight patients were white, one was black, and one was Asian. The right eye was involved in six cases, the left eye in three, and in one case this information was not available. No predilection for any quadrant or superior-versus-inferior location was observed (see Table 1, Table 2.)

Five patients were asymptomatic when the tumor was first discovered. Of

Discussion

Melanocytomas of the uvea are relatively uncommon tumors. Howard and Forrest,10 in a study of 907 pigmented intraocular tumors, found only 5 melanocytomas (an incidence of 0.6%). In a review of 189 iris or ciliary body lesions, or both, originally diagnosed as melanomas, Jakobiec and Silbert7 identified 10 of 189 (5%) as melanocytomas.

Eighteen cases of ciliary body melanocytomas were reported by other authors before 1985. These were summarized by Frangieh et al,11 who added four additional

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Iris and Ciliary Body Melanocytomas Are Defined by Solitary GNAQ Mutation Without Additional Oncogenic Alterations
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To analyze the genetic features of melanocytomas and melanomas of the anterior uvea and assess the value of molecular testing for diagnosis and prognostication.
Retrospective case-control study.
Patients with melanocytoma (n = 16) and melanoma (n = 19) of the anterior uvea.
Targeted next-generation sequencing was performed on formalin-fixed, paraffin-embedded tumor tissue from anterior uveal melanocytic tumors and correlated with clinicopathologic features.
Presence or absence of accompanying oncogenic alterations beyond GNAQ/GNA11 and their association with histologic features and local recurrence.
Hotspot missense mutations in GNAQ/GNA11 were identified in 91% (32/35) of all cases. None of the melanocytomas with or without atypia demonstrated chromosomal imbalances or additional oncogenic variants beyond GNAQ mutation, and none recurred over a median follow-up of 36 months. Additional alterations identified in a subset of melanomas include mutations in BAP1 (n = 3), EIF1AX (n = 4), SRSF2 (n = 1), PTEN (n = 1), and EP300 (n = 1); monosomy 3p (n = 6); trisomy 6p (n = 3); trisomy 8q (n = 2); and an ultraviolet mutational signature (n = 5). Local recurrences were limited to melanomas, all of which demonstrated oncogenic alterations in addition to GNAQ/GNA11 (n = 5). A single melanoma harboring GNAQ and BAP1 mutations and monosomy 3 was the only tumor that metastasized.
In this study, anterior segment uveal melanocytomas did not display oncogenic alterations beyond GNAQ/GNA11. Therefore, they are genetically similar to uveal nevi rather than uveal melanoma based on their molecular features known from the literature. Molecular testing can be performed on borderline cases to aid risk stratification and clinical management decisions.
Histopathology and immunohistochemistry of choroidal melanocytoma demonstrated by local resection: A case report
2021, American Journal of Ophthalmology Case Reports
To describe the clinical and histopathological features of a case of choroidal melanocytoma treated by local resection.
A 73-year-old man was referred to our hospital with a clinical diagnosis of choroidal melanoma. His best corrected visual acuity at presentation was 20/20 OU. Ocular fundus examination of his right eye showed a pigmented intraocular tumor. Local resection of the tumor was performed under general anesthesia. Histopathological examination of the excised tumor showed proliferation of round to ovoid cells with abundant cytoplasm containing many melanosomes and uniform nuclei and these histopathological findings were compatible with a diagnosis of choroidal melanocytoma. Visual acuity of 20/200 OD has been maintained for over 4 years without local recurrence.
Clinical diagnosis of choroidal melanocytoma, especially differentiation from melanoma, is difficult and challenging. Local resection of the tumor allowed study of the histopathological features of the choroidal melanocytoma and maintained tolerable vision in the current case.
Orbital melanocytoma: When a tumor becomes a relieving surprise
2018, American Journal of Ophthalmology Case Reports
Citation Excerpt :
These criteria can be crucial in differentiating melanocytoma from malignant melanoma.2,8 Prominent vascular network, calcification as well as cystic spaces filled with fibrinous material were also described in melanocytomas.18 Immunohistochemical positivity for HMB-45 and S-100 indicated that this tumor is derived from melanocytes.1–4
Melanocytomas are rare pigmented tumors that arise form melanocytes and have been reported in the central nervous system. Orbital melanocytomas “also known as blue nevus” are rarely reported. The occurrence of choroidal melanoma and orbital melanocytomas has never been described.
This is a case of orbital melanocytoma in a 34 year old female who presented with left proptosis and ecchymosis. She has the right eye enucleated to treat a large choroidal melanoma, 6 years earlier. Orbital metastasis was suspected. After orbital imaging and systemic evaluation, incisional biopsy was planned yet the mass could be totally excised and it turned out to be melanocytoma. The condition was not associated with nevus of Ota and the patient is not known to have any predisposing condition for melanocytic lesions.
Melanocytoma and malignant melanoma share the same cell of origin. The benign course, the well differentiated cells, absence of anaplasia and the positive reaction to Human Melanoma Black-45 (HMB-45) and S-100 proteins established the diagnosis of the former. Such diagnosis was a relief for this one eyed patient.
(HMB-45:human melanoma black-45).
Ocular ultrasound findings in optic disk melanocytoma
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To describe the echographic characteristics of optic disk melanocytoma using a high resolution 10–20 MHz ophthalmic ultrasound.
We conducted a 10-year retrospective review finding 9 cases with optic disk melanocytoma. The echographic studies were performed by the same experienced ophthalmologist. The form and density of the tumors were evaluated with B-scan ultrasound. Internal reflectivity and vascularity of the tumors were assessed with a standardized A-scan. Base (vertical and horizontal) and height of the tumor were obtained by using both ultrasounds AB modes.
The mean age at diagnosis was 43.88 years. There was no evidence of abnormal tumor vascularization in any of the cases. Mean (SD) vertical measurement of the base was 2.53 mm (±1.47). Mean (SD) horizontal measurement of the base was 2.49 mm (±1.03). Mean height (SD) was 1.52 mm (±0.88). Of the assessable cases, 78% had high internal reflectivity, the remaining 22% had medium-high internal reflectivity. All tumors’ internal structure was characteristically homogeneous. Mean follow-up was 33.6 months.
Melanocytomas are small, benign tumors that are highly assessable by ocular ultrasound when their elevation surpasses 0.5 mm. In our study, the internal reflectivity ranged from high to very high, unlike other malignancies such as choroidal melanoma which tend to present with low internal reflectivity. The avascularity of the tumor is a common finding. Ultrasound is a remarkable tool that helps detect benign characteristics in a pigmented optic disk tumor and helps establish a more reliable diagnosis.
Describir las características ecográficas del melanocitoma de nervio óptico utilizando un ultrasonido oftálmico de alta resolución (10-20 Mhz).
Serie de casos retrospectiva de 10 años. Se presentan 9 casos de melanocitoma de nervio óptico. El análisis ecográfico fue realizado por el mismo oftalmólogo experimentado. La morfología y la densidad de los tumores fueron evaluadas con ultrasonido modo B. La reflectividad interna y la vascularidad de los tumores se evaluaron con ultrasonido modo A. La base (en sus dimensiones vertical y horizontal) y la altura de los tumores se midieron utilizando ambos ultrasonidos modo AB.
El promedio de edad al diagnóstico fue de 43.88 años. No hubo evidencia de vascularidad anormal en ningún caso. El promedio (DE) de la medición vertical de la base fue 2.53 mm (±1.47), la medición horizontal de la base fue 2.49 mm (±1.03), y la media de la altura tumoral fue 1.52 mm (±0.88). Del total de los casos, el 78% tuvo reflectividad interna alta y el 22% restante tuvo reflectividad interna media-alta. El 100% de los tumores tuvieron una estructura interna de características homogéneas. El promedio de seguimiento fue de 33.6 meses.
Los melanocitomas son tumores pequeños, benignos, que fácilmente pueden ser estudiados por ultrasonido ocular cuando su elevación sobrepasa los 0.5 mm. En nuestro estudio la reflectividad interna varió de alta a media-alta, a diferencia de otras afecciones malignas como el melanocitoma coroideo, que se presentan con una reflectividad interna baja. La avascularidad del melanocitoma es un hallazgo común. El ultrasonido es una gran herramienta que nos ayuda a detectar características benignas en un tumor pigmentado del nervio óptico, ayudándonos a establecer un diagnóstico más fiable.
Acute subconjunctival pigmentation with an underlying ciliary body mass: An unusual case presentation
2019, Saudi Journal of Ophthalmology
Citation Excerpt :
EM findings also differ between the 2 types with a corresponding smaller cells, less coarse melanin, and prominent indentations of the nuclear membranes in Type II cells versus giant melanosomes in Type I, which was appreciated in our case by EM thus supporting our diagnosis.13 Demographically, Lo Russo and co-authors summarized a total of 40 cases of CB melanocytoma including 10 cases of their own and concluded an average age of 47 years, 65% prevalence in females, and higher occurrence in white patients (80%) compared to black (10%).13 Following their review in 1999, several sporadic cases have been reported in the English-written literature, the majority of which are describing the challenging clinical diagnosis and the impact of this on treatment modalities other than enucleation which includes local excision, iridocyclectomy with lamellar sclera flap and brachytherapy.14,15,16,17
Intraocular melanocytoma is a rare slowly growing benign tumor that may occur anywhere along the uveal tract including the ciliary body but is more commonly found near the optic disc. It is darkly pigmented and may exhibit fast growth and possibly malignant transformation. Ciliary body (CB) melanocytoma is rare and often misdiagnosed as a melanoma. We are reporting a case of CB melanocytoma in a 74-year old lady with unusual initial presentation of an acute onset of subconjunctival pigmentation and extra-scleral extension of the melanocytoma with coarse melanin granules. The diagnosis of melanocytoma was confirmed by histopathological examination of the prolapsed tissue and by ultrastructural studies. Literature review of similar cases is also summarized.

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^☆: Supported in part by a grant from the Retina Research Foundation, Houston, Texas, the National Institutes of Health (grant no. EY02520), and by an unrestricted grant from Research to Prevent Blindness, New York, New York.

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Original ArticlesMelanocytoma (magnocellular nevus) of the ciliary body: report of 10 cases and review of the literature☆

Abstract

Purpose

Design

Methods

Main outcome measures

Results

Conclusions

Section snippets

Materials and methods

Results

Discussion

Ophthalmology

Am J Ophthalmol

Surv Ophthalmol

Am J Ophthalmol

Am J Ophthalmol

Am J Ophthalmol

Surv Ophthalmol

Am J Ophthalmol

Melanocytoma of the optic disc

Int Ophthalmol Clin

Melanocytoma of the choroid clinically simulating a malignant melanoma

Arch Ophthalmol

Original Articles
Melanocytoma (magnocellular nevus) of the ciliary body: report of 10 cases and review of the literature☆