Presentation, Treatment, and Prognosis of Secondary Melanoma within the Orbit

Abstract

BackgroundOcular melanoma is a rare but often deadly malignancy that arises in the uvea, conjunctiva, or orbit. Uveal melanoma is the most common type, with conjunctival melanoma being the second most frequently observed. Melanoma accounts for 5–10% of metastatic or secondary orbital malignancies, but only a minute proportion of primary orbital neoplasia. The aim of this study was to characterize the clinical presentation, treatment, and prognosis in patients presenting with melanoma metastatic to, or secondary within, the orbit.MethodsA retrospective cohort study of patients presenting to a tertiary referral orbital unit from 1982 to 2016 was performed. Eighty-nine patients with biopsy-proven diagnosis of melanoma within the orbit were included in the study. The clinical notes, radiological imaging, histology, surgical notes, and outcome data for the patients were reviewed. The main outcome measures of interest were the interval between primary malignant melanoma and orbital presentation, survival after orbital presentation, and clinical parameters (such as gender, age at presentation, and treatment approach).ResultsThe commonest primary source of tumor was choroidal melanoma, with conjunctival and cutaneous melanomas being relatively common; eyelid and naso-sinus tumors occurred in a few cases. The mean age at presentation with orbital disease was 65 years (31–97 years). The interval between primary malignancy and orbital disease (either local spread/recurrence or true metastatic disease) showed wide variability, with almost one-third of patients having orbital disease at the time of primary diagnosis, but others presenting many years later; indeed, the longest orbital disease-free interval was over 34 years. Twenty-three patients were considered to have had late orbital metastases—that is, at more than 36 months after primary tumor. The median survival following presentation with orbital involvement was 24 months. Patients with tumors of cutaneous origin had worst survival, whereas those with conjunctival tumors had the best prognosis.ConclusionA high index of suspicion for orbital recurrence should be maintained in any patient with prior history of melanoma, however distant the primary tumor is in site or time. Furthermore, giving a prognosis for orbital melanoma remains problematic due to highly variable survival, and further investigation will be necessary to understand the likely genetic basis of this phenomenon.

Two Late Recurrences of Conjunctival Melanoma

“…A third explanation for the development of melanoma that we considered is that the lesion is a primary cutaneous melanoma or a secondary lesion of another (nonconjunctival) melanoma [10]. Histologically, there was no relation between the subcutaneous nodule and the cutaneous melanocytes in our patient, indicating that a primary cutaneous origin is very unlikely.…”

Detection of mutations in SF3B1, EIF1AX and GNAQ in primary orbital melanoma by candidate gene analysis

“…One of our patients harbouring the change (case 9) did indeed have late onset metastasis to the brain (13 years after diagnosis). It is also interesting to note that secondary melanoma within the orbit was noted to have frequent late recurrence, and the incidence of SF3B1 in these tumours could be studied [37].…”

Primary Orbital Melanoma: Presentation, Treatment, and Long-term Outcomes for 13 Patients

“…After tumor reactivation, however, it followed a very aggressive course (Figure 2 C), requiring several palliative procedures, and the patient died 13 months later. Late metastatic or secondary melanoma to the orbit has been reported ( 45 , 46 ), and similar genetic factors might possibly control the late recurrence of both primary and secondary orbital melanomas; alternatively, the orbital milieu might pre-dispose to a prolonged tumor latency before late recurrence.…”