Unilateral multifocal uveal melanoma is a neoplastic curiosity that
needs to be clinically distinguished from metastatic carcinoma and metastases
of cutaneous melanoma. We describe a patient with a small posterior choroidal
melanoma who developed 2 separate nonpigmented angle tumors in the same eye
after treatment. The angle tumors simulated metastases of either the primary
choroidal melanoma or an unrecognized systemic malignancy. When the eye was
removed, we found an occult ring melanoma of the ciliary body with invasion
of the angle.
A 71-year-old woman was referred for the evaluation of a pigmented tumor
in her right eye. An examination revealed a visual acuity of counting fingers
at 3 ft OD and 20/40 OS. Positive findings included bilateral cataracts and
a 6-mm heart-shaped, pigmented choroidal tumor above the right optic disc
(Figure 1A). A 3-mm flat, pigmented
nevus was present temporal to the left macula. A standardized A-scan of the
right choroidal tumor showed low internal reflectivity and a tumor height
of 2.5 mm. A general medical evaluation and laboratory studies showed no evidence
of systemic malignancy. The tumor was treated with a radioactive plaque. A
week after surgery, 2 light-gray lesions approximately 1 mm in size were seen
at the root of the right iris at the 7- to 8-o'clock and 10-o'clock positions
(Figure 1B). The lesions were observed
for 4 months but did not enlarge; an iris biopsy was performed and showed
spindle melanoma cells. Further evaluation found no evidence of malignancy
elsewhere, including the skin. The patient opted for removal of the eye. A
histopathologic examination revealed a largely necrotic (>95%) choroidal melanoma
above the optic nerve (Figure 2A).
No mitotic figures were seen among the residual spindle and epithelioid cells.
A mixed cell–type melanoma had encircled the ciliary body and focally
invaded the angle (Figure 2B). When
40 fields were viewed under high-power magnification, 2 mitotic figures were
seen. Both tumors were positive for the HMB-45 antigen. Results of serial
sections confirmed that the 2 melanomas were not contiguous.
A, A 6-mm pigmented tumor (arrows)
is present above the right optic disc (arrowhead). The view of the fundus
is hazy as a result of cataract. B, Two light-gray tumors (arrowheads) are
barely discernible in the angle of the right eye.
A, The enucleated right eye reveals
a predominately necrotic melanoma (arrow) adjacent to but not involving the
optic nerve (hematoxylin-eosin; original magnification ×6). B, A coronal
section several millimeters behind the limbus shows the ciliary body entirely
replaced with a mixed cell–type melanoma (hematoxylin-eosin; original
At least 16 cases of unilateral multifocal uveal melanoma have been
reported in the literature.1,2
Our patient had no predisposing risks for uveal melanoma such as melanosis
oculi or neurofibromatosis. She did not have bilateral diffuse uveal melanocytic
tumors. The near-simultaneous recognition of both an anterior and posterior
segment melanoma in the same eye is highly unusual.3
The time sequence in which 2 discrete anterior segment tumors were detected
in our patient raised the possibility of ocular metastasis of either the recently
treated choroidal melanoma or an occult systemic malignancy. Prior to biopsy,
the second possibility seemed more likely because the angle tumors were nonpigmented.
The ring melanoma, which was clinically undetected because of minimal elevation,
probably represents a primary uveal malignancy.
The biological basis for multifocal uveal melanoma is unknown. The possibility
of occult ring melanoma needs to be considered when multiple angle tumors
are found, even in an eye harboring a discrete posterior melanoma.
Corresponding author: Curtis E. Margo, MD, MPH, Department of Ophthalmology,
Watson Clinic LLP, 1600 Lakeland Hills Blvd, Lakeland, FL 33805 (e-mail: firstname.lastname@example.org).
Hammer ME, Margo CE. Unilateral Multifocal Uveal Melanoma With Occult Ring Melanoma. Arch Ophthalmol. 2002;120(8):1090–1091. doi: