A 62-year-old woman with a history of extensive Crohn's disease diagnosed 25 years prior and a strong family history of colorectal carcinoma, presents for her scheduled surveillance colonoscopy. Over the past few months, she has reported intermittent mild abdominal discomfort and a recent episode of dark-colored stool, though denies frank hematochezia or significant weight loss. Her vitals today are stable: temperature 37.1 C, blood pressure 128/78 mmHg, pulse 82/min, respirations 16/min, and oxygen saturation 99% on room air. Physical examination reveals mild diffuse abdominal tenderness without rebound or guarding. Her conjunctivae are mildly pale. During the colonoscopy, a large, sessile, velvety polyp measuring 2.5 cm is identified in the ascending colon and removed. Histopathological analysis confirms it is a neoplastic polyp with predominantly villous architecture and high-grade dysplasia, exhibiting features consistent with the type of adenoma known to have the highest malignant potential. Given her presentation, comorbidities, and the histopathological findings, what is the most appropriate next step in her management and surveillance strategy?