The appearance of tissue inside the colon provides medical professionals with visual information regarding intestinal health. Descriptions of tissue color, such as “tan tissue,” are observational findings noted during an endoscopic procedure like a colonoscopy or in a pathology report. These visual cues suggest a deviation from the expected healthy appearance, prompting closer examination or removal. Microscopic analysis of any tissue exhibiting an unusual color or structure then determines the final diagnosis.
The Standard Appearance of Healthy Colon Tissue
A healthy colonic lining, known as the mucosa, generally presents with a soft, glistening pink to light reddish color when viewed through a colonoscope. This coloration is due to the rich, underlying network of capillaries that nourish the tissue. The surface is smooth, moist, and features a repeating pattern of pouches and folds.
Visual inspection relies on light transmission through epithelial cells to the underlying vascular supply. A change in the pink color suggests an alteration in the tissue’s thickness, hydration, or cellular composition. Inflammation often leads to a deeper red appearance due to increased blood flow, while a tan or pale color points to a reduction in visible vascularity.
Specific Findings Associated with Tan Tissue Appearance
The term “tan” or “pale tan” describes lesions that lack the redness of inflamed tissue or the pink of healthy mucosa. This appearance signifies a change in the epithelial layer or a mass beneath the surface. Hyperplastic polyps, for example, frequently present as small, pale, or sessile (flat) lesions, usually less than five millimeters in size.
Hyperplastic polyps are benign epithelial growths and are the most common type of polyp found during colonoscopy. They can be visually challenging to distinguish from other, more concerning growths. Their paler color results from a unique cellular overgrowth pattern that does not involve the cell abnormality seen in other polyp types.
Sessile serrated lesions (SSLs) are another group that can appear tan or pale, and they are considered precursors to a subset of colorectal cancers. SSLs are subtle, often appearing flat or slightly raised with a color similar to the surrounding healthy mucosa. They may also have an indistinct border or a mucus cap. Their pale color makes them difficult to detect without careful inspection.
A yellowish-tan color may indicate a colonic lipoma, which is a benign tumor composed of fat cells. Lipomas are submucosal, meaning they grow beneath the inner lining of the colon. Their yellow appearance is characteristic of the underlying adipose tissue. They can sometimes grow large enough to cause symptoms or warrant removal to confirm the diagnosis.
Diagnostic Evaluation and Follow-Up
When a medical professional identifies tan tissue or a suspicious lesion during a colonoscopy, the tissue is removed via a polypectomy. The excised tissue is sent to a pathology laboratory for microscopic analysis. This analysis determines the precise type of cells involved, such as whether the lesion is a benign hyperplastic polyp or a premalignant sessile serrated lesion.
The pathology report classifies the tissue, confirming the significance of the initial visual finding. Based on this diagnosis, the medical team determines the appropriate surveillance schedule. Finding small hyperplastic polyps may lead to a standard screening interval. Conversely, identifying a sessile serrated lesion requires a more frequent surveillance colonoscopy schedule. The follow-up plan is personalized, considering the size, number, and specific type of abnormality found.