Findings Observed through Contact Endoscopy in ENT

Contact endoscopy plays a crucial role in reinforcing clinical evaluation in otolaryngology as it enables the identification of alterations in various anatomical territories that may not be perceived through other methods. This non-invasive technique works based on the concept of anatomical and functional units.

Normal and Pathological Patterns

In each of the territories, the pathology acquires specific characteristics; however, the overall behavior of the mucosa, in general, is very similar.

Normal Epithelium

In normal squamous epithelium, the cells appear polyhedral and in continuity with each other when observed through contact endoscopy. The mucosa's overall behavior is quite similar, with a regular nuclear-cytoplasmic ratio and homogeneous morphological pattern. The nucleus is round and dark, whereas the cytoplasm has a light blue coloration.

Ciliated Epithelium

The ciliated epithelium, on the other hand, has a distinct appearance when observed via contact endoscopy. The nuclei are round and dark, but the cytoplasm limits are difficult to define.

The nuclei are very close to each other, creating a higher density of nuclei per optic field. The filamentous structures observed during the procedure are due to bundles of cilia. The transition from squamous to ciliated epithelium is also easily observable with contact endoscopy.

Metaplasia

Metaplasia, which is a process where the mucosa transforms, is often observed in glandular orifices scattered throughout the mucosa of the upper aerodigestive tract. This transformation occurs particularly when the mucosa is subjected to damaging factors like smoking, alcohol,

medications, or autoimmune diseases. If the mucosa is damaged due to a triggering agent, metaplasia can occur as a result.

Mucosal Vessels

The technique of contact endoscopy enables us to observe the mucosal vessels in detail. The most superficial microvascular network can be found just below the basement membrane. Although it is possible to see the deeper vessels, they are better observed at the level of the vocal cords.

Angioarchitecture

The blood vessels are parallel to each other and connected by transverse anastomotic vessels. Contact endoscopy provides us with a fascinating image of blood flow through these vessels.

Chronic Inflammation

When using contact endoscopy to observe chronic inflamed mucosa, the general aspect of the squamous epithelium appears homogeneous. However, the size of the nuclei is larger, resulting in an increased nucleus/cytoplasmic ratio.

In cases of chronic inflammation, the mucosa has a higher vascular density due to the increased number and enlargement of blood vessels. Although the organization pattern is homogeneous, the increased vascularity, larger nucleus, and increased nuclearcytoplasmic

ratio are specifically seen in patients with chronic inflammation.

Fungal Infections

Fungal infections can also be identified through contact endoscopy in some cases of chronic inflammation. In addition to the typical pattern of increased diameter of the nuclei, small dark dots that spoil the image can be seen, which are nothing but the fungus itself. Contact endoscopy has identified fungal infections in many cases associated with chronic inflammatory changes or neoplastic lesions in different anatomical sites.

Keratosis

Contact endoscopy can also identify different degrees of keratinization in the same patient and even within the same lesion. Initially, isolated cells without a nucleus are identified. However, it is not possible to identify individual cells in areas of amorphous or laminar distribution.

Leukoplakias

Leucoplakias is a type of oral lesion that can exhibit various cellular alterations , including heterogeneity, hyperkeratosis, and dysplasia, as seen through contact endoscopy. A heterogeneous distribution of cells may indicate the presence of leucoplakia or cancer. Additionally, keratosis can occur at different degrees in other clinical conditions such as chronic inflammation, papillomas, and tumors.

Dysplasia

In most cases of dysplasia, there is alteration at the superficial layers, which are accessible to contact endoscopy. Most tissue alterations are necessary for the diagnosis of dysplasia by a pathologist and are identifiable by contact endoscopy. Specifically, alterations in size, shape, and coloration of nuclei, altered nucleus cytoplasm ratio (dyskaryosis and anisokaryosis) and keratosis.

The microvascular alterations that happen in a dysplastic lesion are fundamental to understanding pathology and, hence, its treatment. The normal microvasculature is substituted by vessels with varying degrees of alterations in the displasia. When the vascular network becomes disorganized and irregular and has passed the boundary of the basement membrane, which is damaged, thus allowing the vessels to penetrate the epithelium, the blood vessels are now just to be with the epithelium normally, you don't see that because of the basement membrane, and there is a breach in the basement.

Tumor

In carcinoma, contact endoscopy identifies the marked cellular irregularity, so there will be prominent new typical regions and heterogenicity. The nuclei have varied sizes, shape, and coloration. The cytoplasm ratio is very irregular. Sometimes, nuclear inclusion, prominent nucleoli, and mitosis are noticed. The angioarchitecture is also very disturbed.

The blood vessels are atypical, with differences in size and shape, but also ectasias, hemorrhages, and reduced blood flow, with results in thrombosis. Depending on the anatomical region of the tumor, distinct images can be observed.

In places where the tumor growth infiltrates the deep places but does not reach the surface. Vascular alterations can be identified with normal superficial epithelial cells. The direct demonstration in vivo and situ of tumoral patterns in the operating room and the outpatient clinic is a reality.

Contact endoscopy also allows the assessment of transition areas, the identification of preliminary stages of disease, guidance of biopsies, guidance of sample collection for cytology, establishment of safe margins, and demonstration of different diseases.

Papilloma

The direct application of the contact endoscope allows the identification of typical vascular loops. The degree of visualization of vascular structure depends on the density of the keratosis that is associated with the disease in some cases. With the vital stain, it is possible to identify the typical koilocytes (ballooned cells) and inflammatory infiltrates. Koliocytes are typical of papillomavirus-infected cells.

Hope you found this blog helpful for your Basic Sciences Preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs. 

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