Patterns of Small Bowel Disorders The most common indication for histologic assessment of small bowel mucosa is to evaluate for a malabsorption disorder. Although the spectrum of small intestinal diseases that can result in symptoms of malabsorption can seem daunting…
Gastric carcinoma is the second most common gas-trointestinal (GI) cancer worldwide, only behind colorectal carcinoma, with more than 1 million cases diagnosed annually. With the increasing use of endoscopy, the diagnosis of early gastric cancer is more frequent, and previously…
The recognition of the central role of Helicobacter pylori in the development of what was once the most common form of chronic gastritis has elicited a significant interest in non-neoplastic gastric pathology. This has been paralleled by easier access to…
Squamous Papillomas Clinical Features These are uncommon, incidental findings at endoscopy that usually occur in women in the fifth decade of life. The vast majority are solitary; some may present as a papillomatosis. They are thought to be a reactive…
The esophagus is designed to simply serve as a conduit to carry food into the stomach. It does not have any digestive, endocrine, or metabolic role. As a result, most non-neoplastic disorders affecting the esophagus are a result of mechanical,…
The neoplasms described in this comprehensive chapter are a heterogeneous group of tumors, having for the most part uncertain histogenesis and no known normal tissue counterpart. Each is characterized by its own distinctive clinical and pathologic features. These tumors can…
In previous editions of this textbook, several entities of uncertain type were placed into either benign or malignant categories. Although these entities still remain an enigma with regard to line of cellular differentiation, larger clinicopathologic studies of each of these…
This chapter discusses a heterogeneous group of benign tumors or pseudotumors, many of which are characterized by abundant myxoid stroma (intramuscular myxoma, juxta-articular myxoma, cutaneous myxoma, ganglion). Evidence indicates that the cells in these lesions are fibroblastic or have some…
Benign extraosseous cartilaginous lesions are uncommon and usually present as tumorlike masses. In the past, the term soft part chondroma or extraskeletal chondroma was used arbitrarily for small, well-defined, solitary nodules of hyaline cartilage that are unattached to bone and…
The overwhelming majority of human tumors showing melanocytic differentiation occur in the skin and represent benign melanocytic nevi, their variants, and malignant melanomas. However, a small percentage of tumors showing melanocytic differentiation occur in unusual locations, such as the meninges…