Primary orbital melanoma masquerading as vascular anomalies

To review two cases of primary orbital melanoma presenting like orbital vascular anomalies.

Retrospective review of clinical presentation, treatment, radiology and pathology for two patients under the care of the Orbital Clinic at Moorfields Eye Hospital.

Both lesions presented with the appearance and behaviour of vascular anomalies. In one case, a spindle cell melanoma appeared to be a low flow vascular anomaly with a loculated secondary haemorrhage and, in the other case, a melanoma of soft parts was considered to be an arteriovenous malformation and responded partially to embolisation.

Primary malignant melanoma may present as a secondary vascular lesion of the orbit and this very rare tumour should be considered in the differential diagnosis of any vascular anomaly.