Patterns of regional and distant metastasis in patients with conjunctival melanoma: experience at a cancer center over four decades.

OBJECTIVE: The regional lymph nodes generally are believed to be the most common first site of metastasis for conjunctival malignant melanoma, but the pattern of nodal metastasis in this disease has not been well established. The goal of this study was to determine the frequency, location, and timing of regional lymph node metastasis in patients with conjunctival melanoma treated at one cancer center over four decades.

DESIGN: Retrospective case series.

PARTICIPANTS: Twenty-seven patients.

METHODS: The clinical records of 27 patients with conjunctival malignant melanoma were reviewed retrospectively.

MAIN OUTCOME MEASURES: The rates of local conjunctival recurrence, regional nodal metastasis, and distant metastasis were analyzed along with overall survival. The follow-up time ranged from 2.5 to 17 years (median, 6 years).

RESULTS: Eleven patients (41%) experienced clinical regional lymph node metastasis 1.5 to 6.0 years (mean, 3.2 years) after the initial diagnosis. The involved lymphatics were the preauricular (parotid) nodes in 8 patients (73%), the submandibular nodes in 1 patient (9%), and the deeper cervical nodes in 2 patients (18%). In seven patients (26%), distant metastasis developed without evidence of prior or concurrent regional nodal disease. Patients in whom distant metastasis developed without clinical evidence of regional nodal involvement were more likely to have had local conjunctival recurrence (P = 0.03) and a higher number of local recurrences (P = 0.05) compared with patients with regional lymph nodes as the site of first metastasis. The 5- and 10-year overall survival rates were 74% and 41%, respectively.

CONCLUSIONS: Regional lymph node metastasis occurred in a higher percentage of patients with conjunctival malignant melanoma than has been reported previously. Preauricular lymph nodes were most commonly involved. Distant metastasis without prior or concurrent lymph node involvement was not a rare event.