Endoscopy is a medical procedure that uses a flexible tube equipped with a light and a camera (an endoscope) to visually examine the interior lining of the digestive tract. Physicians routinely use this technique for screening, diagnosis, and monitoring conditions affecting the esophagus, stomach, and colon. The procedure provides a direct, magnified view of internal organs to detect visual deviations from a healthy state.
Identifying Visual Signs of Abnormality
A healthy gastrointestinal lining, or mucosa, presents as a smooth, uniform surface with a consistent color, typically ranging from pale pink to a rosy salmon shade. The esophagus tissue is pale and glistening, while the stomach and colon often display a richer pink hue. A normal vascular pattern, where small blood vessels are visible just beneath the surface, indicates proper tissue health.
Abnormalities are recognized through changes in three categories: color, texture, and surface contour. Color changes often involve pallor (indicating anemia or atrophy) or intense redness (erythema), a sign of inflammation. Texture changes might present as a rough, granular, or brittle surface, contrasting with normal smooth tissue.
Deviations in surface contour range from flat, depressed areas to raised, protruding masses. The presence of friability, where the tissue bleeds easily upon light contact, is a visual clue of underlying disease or severe inflammation. Recognizing these characteristics allows the endoscopist to target specific areas for closer inspection and tissue collection.
Common Abnormal Findings and Appearance
Visual abnormalities are categorized into three types: lesions or growths, inflammation, and breaks in the mucosal lining. Lesions are distinct, localized areas that protrude or depress the surface and range widely in shape and size. In the colon, the most common lesions are polyps, which are growths of excess tissue.
Polyps are categorized by their shape, often described using the Paris classification system. A pedunculated polyp is identifiable by its mushroom-like appearance, possessing a distinct head attached to the colon wall by a narrow stalk. In contrast, a sessile polyp lacks a stalk and presents as a dome-shaped, broad-based elevation.
Inflammation, resulting from conditions like gastritis, esophagitis, or colitis, manifests visually as a diffuse or patchy change across the mucosa. In the stomach, gastritis can cause the lining to look thickened and reddened due to congestion, or pale and thin in cases of chronic atrophy. Barrett’s esophagus is a unique presentation where the normal pale-pink squamous lining is replaced by salmon-pink, velvety columnar tissue, a sign of intestinal metaplasia.
Ulceration and erosion represent breaks in the integrity of the mucosal lining, differing primarily in depth. Erosions are superficial, shallow breaks confined to the outermost layer of the mucosa, often seen as small, reddish patches. An ulcer is a deeper lesion that penetrates through the muscularis mucosae, appearing as a crater often covered by a white or yellowish base of dead tissue. A benign ulcer typically has a regular, smooth border, while a malignant one may display heaped-up or irregular margins.
Confirming Diagnosis Through Sample Analysis
Although the visual appearance of abnormal tissue is highly informative, a definitive diagnosis requires a biopsy. The endoscopist obtains a small tissue sample from the suspicious area to confirm the precise nature of the abnormality. This is accomplished by passing specialized tools, such as tiny forceps or snare devices, through a working channel in the endoscope.
Once collected, the tissue sample is immediately placed into a preservative solution like formalin to stabilize the cellular structure. The sample is labeled with the patient’s information and the exact location from which it was taken before transport to a pathology laboratory. This ensures the sample remains intact and correctly identified for subsequent microscopic examination.
In the pathology lab, a histopathologist specializes in tissue analysis. The tissue is processed, embedded in a solid block of paraffin wax, and then sliced into sections only a few micrometers thick. These slices are placed on glass slides and stained with special dyes, most commonly Hematoxylin and Eosin, to make the cell nuclei and surrounding structures visible under a microscope.
The pathologist performs a microscopic analysis, examining the architecture of the tissue and the characteristics of the individual cells. This evaluation distinguishes between a benign condition, a specific type of inflammation (like Crohn’s disease versus ulcerative colitis), or the presence of precancerous changes (dysplasia) and malignant cells. The final pathology report correlates these cellular findings with visual observations to establish the most accurate diagnosis.
Interpreting Clinical Significance and Follow-Up
The clinical significance of an abnormal finding is determined by combining visual information from the endoscopy with the cellular analysis from the pathology report. For example, the size and shape of a polyp (large, sessile, or depressed morphology) coupled with a finding of high-grade dysplasia determines the level of risk. This combined assessment dictates the appropriate next steps: surveillance or interventional treatment.
For low-risk findings, such as small hyperplastic polyps, mild inflammation, or non-dysplastic Barrett’s esophagus, the standard pathway is surveillance. This involves monitoring the area with repeat endoscopies at defined intervals, such as every three to five years, to ensure the condition does not progress or recur.
When the pathology reveals high-risk features like high-grade dysplasia or early-stage cancer, the significance changes from monitoring to immediate intervention. The endoscopist proceeds with therapeutic procedures to remove or destroy the abnormal tissue. Endoscopic Mucosal Resection (EMR) or Endoscopic Submucosal Dissection (ESD) are techniques used to remove larger lesions entirely by lifting the inner lining and excising the abnormal growth.
For precancerous conditions like high-grade dysplasia in Barrett’s esophagus, ablation techniques such as Radiofrequency Ablation (RFA) may destroy the remaining abnormal tissue with heat energy. After successful intervention, the patient is placed on an intensive surveillance schedule, often involving repeat endoscopies every three to twelve months, to ensure complete eradication and promptly detect any recurrence.