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Conjunctival Malignant Melanoma
| Moderator: Elmer Tu, MD Associate Professor of Clinical Ophthalmology Director, Cornea Service |
Presenter: Brittany Osgood, MD |
Case Report
A 69 year-old white male was referred to the cornea clinic after biopsy of a conjunctival lesion of the right eye was noted to be malignant melanoma with involvement of the margins. According to the patient, he had noted a “colored spot” on the conjunctiva for many years, but had noted recent growth over the past year. His medical, surgical, social and family histories were all unremarkable.
The best corrected visual acuity was 20/25 in the right eye and 20/20 in the left. His motility and confrontation visual fields were full bilaterally. On slit lamp examination of the right eye, a conjunctival graft was noted temporally with pigment on the graft, and abnormal vessels were noted superotemporally. Examination of the left eye was normal. Gonioscopy was normal in both eyes. No lymph nodes were palpated and the dilated fundus exam was normal.
A wide resection of the main lesion was planned. This was conducted in June 2009 and while in the OR, another small superior pigmented lesion was noted which was also removed, along with 2 map biopsies in the superior and inferior fornix. Cryotherapy was applied to the margins and absolute alcohol to the limbus. An amniotic membrane was used for resurfacing.
On pathology, the main lesion was noted to be malignant melanoma with a thickness of 0.34mm, arising in the context of primary acquired melanosis (PAM) with atypia (figure 1), with extension to the superior margin. The smaller superior lesion was also noted to be melanoma (figure 2) and the 2 map biopsies were negative.
The patient was referred to oncology and a sentinel lymph node biopsy performed in July 2009 was negative.
Discussion
Surgical treatment of keratoconus can be challenging in a patient with mental retardation. Careful selection of patients who are good candidates is essential, and requires observation of the patient, as well as questioning of the family or caretaker. A combative and noncooperative patient endangers not only the eye and graft, but also makes follow-up examinations extremely difficult. The second case demonstrates some of the difficulties in managing a traumatic hyphema with corneal blood staining in a young child. Although corneal blood staining in an adult can often be observed, in a young child the risk of amblyopia may necessitate earlier intervention. Since our patient was slightly on the older end of those susceptible to amblyopia, it was elected to observe the patient carefully. However, the use of patching in the unaffected eye can prevent amblyopia.
The final case involves a challenging presentation of malignant melanoma of the conjunctiva. It is important to note that the vast majority of cases arise from PAM, and especially PAM with atypia. Any patient with PAM must be monitored carefully, and malignant transformation suspected if there is a change in elevation or increased vascularity develops. Although not applicable in our patient’s case, it is good practice to send pterygia for pathologic examination after they are excised, as they can sometimes harbor a malignant melanoma.
Background on Conjunctival Malignant Melanoma
Conjunctival malignant melanomas are rare, occurring 40 times less than choroidal melanomas and 500 times less than cutaneous melanomas. They can arise from PAM in 60-77% of cases, a pre-existing nevus in 20%, or rarely de novo. In the setting of PAM with atypia, 50% give rise to malignant melanoma within 2 ½ years.
— Taken from the Cornea Grand Rounds, July 23, 2009.
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