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Concise Pathology, 3e
| Part B. Systemic Pathology > Section IX. The Gastrointestinal System > |
Chapter 41. The Intestines: III. Neoplasms
Sections: Primary Epithelial Tumors, Primary Nonepithelial Neoplasms, Metastatic Neoplasms.
Topics Discussed: gastrointestinal disease; neoplasms.
Excerpt:"Many different pathologic processes involving the mucosa result in polyps that project into the lumen of the intestine. Intestinal polyps may be foci of epithelial hyperplasia, epithelial neoplasms, hamartomas, or retention polyps. Not all polyps are associated with epithelial proliferation. Inflammation (inflammatory polyps), lymphoid hyperplasia (lymphoid polyps), and mesenchymal neoplasms (lipoma, leiomyoma) may also result in polyps (Table 41-1).Adenomas of the colon are present in 20–30% of all individuals over the age of 50 years. They are of two major types: tubular and villous (Figure 41-1). Colonic adenomas are associated with genetic mutations identical to those seen in colon cancer. The number of mutations in adenomas is less than in carcinoma but increases as the adenoma enlarges and becomes more dysplastic (the adenoma  carcinoma sequence).Tubular adenomas account for over 90% of colonic adenomas. They are commonly multiple, with 10–20 lesions present in some patients, and are pedunculated with a well-defined stalk (Figures 41-1B and 41-2).Hamartomas are uncommon lesions in the intestinal mucosa and present as polyps. They can be found as isolated lesions..."
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