A 70-year-old man with colorectal carcinoma has chronic occult blood loss. What type of colonic polyp is likely present?

The presence of chronic occult blood loss in a 70-year-old man with colorectal carcinoma suggests the likelihood of a colonic polyp associated with dysplasia. Tubular adenomas are the most common type of adenomatous polyp found in the colon and are known to have the potential for malignant transformation. In patients with colorectal cancer, particularly those with a history of chronic blood loss, tubular adenomas may be present as precursors to cancer.

These polyps can cause symptoms such as bleeding, which fits with the patient's presentation of occult blood loss. Tubular adenomas are also characterized by their tubular architecture and typically grow slowly, allowing for the accumulation of premalignant changes over time. This association with colorectal cancer and the characteristic of causing bleeding makes tubular adenomas the most likely type of polyp present in this patient.

In contrast, hyperplastic polyps, while common, are generally considered benign and do not carry a significant risk of progression to cancer. Invasive squamous carcinoma is not typically found in the colon, as colorectal carcinoma arises from adenomatous changes rather than squamous ones. Juvenile polyps, although they can cause bleeding, are largely seen in younger individuals, not in a 70-year-old man with definitive