Conjunctival melanoma: the role of conservative surgery and radiotherapy in regional metastatic disease

OBJECTIVE: To evaluate prognostic factors and determine the role of conservative surgery and radiotherapy in managing metastatic conjunctival malignant melanoma (MM) involving preauricular/submandibular lymph nodes. METHOD: A retrospective analysis (1990-2003) of clinical and histopathologic data from 12 patients presenting with regional metastases after failed local treatment for conjunctival MM. Patients received a common, multispecialty, conservative management approach: wide local excision, topical cryotherapy or radiotherapy to conjunctival MM (orbital exenteration for more advanced local disease), lumpectomy, and adjuvant "ring" radiotherapy of regional metastases, with chemotherapy for distant metastases. RESULTS: Median age at primary diagnosis was 51 (range 28-86) years with equal sex predilection. Six of the 12 patients had primary tumors of the bulbar conjunctiva; the remainder arose in the palpebral conjunctiva, the caruncle, or the fornix. Of 11 originating in primary acquired melanosis (PAM), 2 were amelanotic. Epithelioid tumor cells were noted histologically in seven of eight specimens in which cell type could be determined. Eight tumors metastasised to preauricular nodes, three to submandibular and one to both, with a median interval of 23 (range 12-108) months after primary diagnosis. After conservative surgery and "ring irradiation," 7 of 12 patients remained free of regional nodal relapse at median interval of 16 (range 3-126) months. Five patients developed regional nodal recurrence at median interval of 11 (range 6-13) months, 3 of whom were within radiotherapy portals. Eight patients developed distant metastasis at median interval of 44 (range 22-138) months. Eleven patients had tumor-related death. The mean Kaplan-Meier adjusted survival time after primary diagnosis was 76 months with death ensuing postregional metastasis within a median 18 (range 4-127) months. The sole survivor's follow-up duration was 56 months. CONCLUSION: Locoregional metastasis after treatment for conjunctival MM is associated with a poor prognosis. Both epithelioid tumor cells and PAM are associated with disseminating disease and poorer outcome. Literature review has failed to demonstrate advantages of mutilating radical surgery over a conservative approach in this rare disease.