Sentinel lymph node biopsy for conjunctival malignant melanoma: surgical techniques

BACKGROUND The purpose of this report is to examine the viability and safety of preoperative lymphoscintigraphy and radio guided sentinel lymph node (SLN) biopsy for conjunctival melanoma, and to identify the best technique to perform this procedure. METHODS Three patients diagnosed with malignant melanoma of the conjunctiva underwent lymphoscintigraphy and SLN biopsy using a dual technique comprising isosulfan blue dye and technetium Tc 99m sulfur colloid. Each patient was anesthetized and the conjunctival melanoma was excised. SLNs were localized by a gamma probe, identified according to radioactivity and sentinel blue printing, and dissected, along with drainage of the associated lymphatic basins. The SLNs were evaluated by a pathologist using hematoxylin-eosin staining following serial sectioning and immunohistochemistry using a triple melanoma cocktail (S-100, Melan-A, and HMB-45 antigens). RESULTS Two SLNs were stained in the jugular chain during preoperative lymphoscintigraphy in the first patient, two SLNs were identified in the preauricular and submandibular areas in the second patient, and two SLNs were identified in the submandibular and parotid areas in the third patient. All lymph nodes identified by lymphoscintigraphy were dissected and identified at surgery with 100% accuracy in all three patients. All SLNs were histologically and immunohistochemically negative. Patients had good cosmetic and functional results, and maintained their visual acuity and ocular motility. CONCLUSION Patients with conjunctival melanoma can undergo preoperative lymphoscintigraphy and SLN biopsy safely using radioactive technetium and isosulfan blue dye.