Primary malignant melanoma of the lacrimal sac.

Primary malignant melanoma of the lacrimal sac is extremely rare. It is usually diagnosed at an advanced stage after excision or biopsy of a tumour. We treated a 59-year-old man with tearing and bloody discharge from the right eye. Clinical examination revealed a firm, localised mass at the inner canthus consistent with a lacrimal sac swelling. Sac washout demonstrated obstruction to entry into the lacrimal sac with a reflux of blood-stained fluid. The pathological findings and the immunohistochemical studies showed a malignant melanoma of the lacrimal sac. We performed radical surgery and radiation therapy. Follow-up 4 months after surgery revealed no evidence of recurrence. Because this tumour often presents with symptoms similar to dacryocystitis and may masquerade as a chronic dacryocystitis, ophthalmologists should be aware of this disease entity when encountered with patients with epiphora and mass in the medial canthal area.