Combined surgery and cryotherapy for diffuse malignant melanoma of the conjunctiva

Abstract

Two patients who had refused exenteration for widespread conjunctival melanoma were treated by a combination of cryotherapy and surgical excisions. Cryotherapy was delivered only to the extensive areas of flat intraepithelial melanocytic proliferation (precancerous melanosis), while the surgical excisions were performed on the focal nodules, representing localized invasive melanoma. In our two patients, the invasive nodules measured, respectively, 1.2 and 1.5 mm in greatest thickness, placing them in a low to borderline risk group for metastasis. Repeated cryoapplicatons were required to control the widespread flat intraepithelial disease. The conjunctiva tolerated these procedures well because the substantia propria is not sacrificed as it must be in surgical conjunctivectomy, allowing comparatively normal reepithelialization to occur from adjacent zones, after the treated epithelium containing the melanocytes sloughs. No evidence of invasive melanoma (cancerous melanosis) has developed in any of the cryotreated areas of intraepithelial disease (precancerous melanosis); sequential biopsies have established that the atypical melanocytes have disappeared from the epithelium.