A 52-year-old man from Delhi undergoes left total thyroidectomy for papillary thyroid carcinoma. During mobilization of the left lobe, the surgeon observes the left recurrent laryngeal nerve (RLN) is intimately involved with tumor. Careful dissection is attempted, but the nerve cannot be separated from the tumor without risk of transection. The tumor is adherent to approximately 2 cm of the nerve. What is the most appropriate intraoperative decision?