Conjunctival melanoma involving the lacrimal drainage system
Reviewed by James Hsuan

A total of 52 patients were diagnosed with conjunctival melanoma over a period of 17 years, 17 of whom required orbital exenteration. Five of these were found to have melanoma involving the lacrimal drainage apparatus (LDA). One was evident clinically prior to exenteration, one was found to have sac involvement during exenteration, and another was discovered only on histological examination post-exenteration. The two remaining cases developed recurrent disease in the lacrimal sac two to three years post-exenteration. The authors recommend sac and proximal duct excision as a routine during exenteration for conjunctival melanoma. This is a very interesting paper with a high rate of LDA involvement compared to previous reports. The authors speculate on the mechanism of spread to the lacrimal sac, but it is noteworthy that all patients had undergone a previous biopsy of the lesion, and many had multiple previous resections. The risk of seeding of melanoma from biopsy or incomplete excision is well known, and this must be considered as a likely cause for the LDA spread. It is also of interest that the canaliculi were involved in only one patient. This reinforces the seeding hypothesis, and the message that histologically normal canaliculi should not reassure the surgeon that the sac or duct are definitely free of disease. 

Malignant melanoma of the lacrimal drainage apparatus complicating conjunctival melanoma.
Satchi K, McKelvie P, McNab AA.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:207-10.