Sentinel Lymph Node Biopsy in the Setting of Conjunctival Melanoma: Report of Two Cases and Literature Review

Objective: To report two cases of conjunctival melanoma (CM) that underwent sentinel lymph mapping (SLNM) and sentinel lymph node biopsy (SLNB) with good results. Introduction: Conjunctival melanoma (CM) is a very rare malignancy, with an incidence of less than one per million cases per year. Metastatic dissemination may occur via lymphatic or hematogenous routes. The regional lymph nodes most commonly involved in the head and neck region are found in the deep cervical node chain and in the parotid gland. The management of the lymph nodes in patients with CM is debatable with some authors recommending SLNM with SLNB. The indications for performing SLNM and SLNB are CM with a thickness of 1 mm or greater. Case report: Two patients diagnosed with CM underwent SLNM and SLNB with complete surgical resection of the conjunctival lesions and superficial parotidectomy as part of the SLNB. Final pathology reported confirmed a complete resection of the lesions and a negative SLNB. The procedure was performed without any postoperative complications. Both patients on follow-up are free of disease without evidence of local or regional recurrence. Conclusion: Evidence of the accuracy SLNM and SLNB in CM in the literature is sparse. We report on two cases where the identification of the SLN was accurate with no postoperative complications. We believe based the available evidence that SLNM and SNLB is feasible, accurate, with a low complication rate in patient with CM. Introduction Conjunctival melanoma (CM) is a rare malignancy with an incidence of 0.15 to 0.49 cases per million persons per year [1,2]. It is a very aggressive non-cutaneous neoplasm that represents only 5% of ocular melanomas with a 10-year mortality rate of 30% [3,4]. It is identified more frequently in the elderly population (53% of the cases), and in Caucasians (94% of the cases) [5]. The main clinical manifestations are a pigmented lesion, lump, or swelling in the conjunctiva in 83% of the cases. In approximately 61% of the cases the lesion is usually located at the limbal conjunctiva and in 46% of the cases in the temporal quadrant of the eye [5]. Metastases can be detected with positron emission tomography / computed tomography (PET/CT). However, micro-metastasis through the lymphatic system can only be detected with sentinel lymph node mapping (SLNM) and sentinel lymph node biopsy (SLNB) [6]. The aim of this study is to present two cases of CM were SLNM and SLNB was performed as part of their management with adequate identification of the SLN with no added morbidity. Case 1 A 72-year old male, with a history of chronic irritation of the left eye for more than two months, was evaluated by an ophthalmologist who diagnosed a CM and send him to our clinic. We identified two pigmented lesions, one of approximately 1 cm in size and another of approximately 2 cm in size. Both lesions had irregular borders, one was in the temporal region, and the other on the nasal region of the eye (Figure 1). He was initially treated with Mitomycin C for 16 days without any objective response. After a multidisciplinary review of the case, it Correspondence to: Rodrigo Arrangoiz, Sociedad Quirúrgica S.C. at the American British Cowdray Medical Center. Department of Surgical Oncology and Head and Neck Tumors. Av. Carlos Graef Fernandez # 154 – 515 Colonia Tlaxala, Delegación Cuajimalpa Mexico City, Mexico 05300, Tel: 52551664 7200; E-mail: rodrigo.arrangoiz@yahoo.com