Week 1 Histopathology Flashcards
What is this urothelial slide indicative of?
Urothelial carcinoma Note the enlarged, hyperchromatic nuclei, when compared to normal urothelium. These atypical cells fill the entire thickness of the epithelium, which is called “carcinoma in situ”
What is this image from the larynx?
An example of a “keratin pearl,” which helps the pathologist to establish that the cell of origin is a squamous epithelial cell carcinoma invasive
What is this? How do you know?
Squamous Cell Carcinoma. The general pattern of the tumor, one of nests and cords of malignant cells, should be readily apparent. Numerous keratin or squamous pearls are evident. Note intact epithelium at far right, which quickly disappears into an ulcer about midway from the right side. Dark blue nests of malignant squamous cells can be seen infiltrating through tissue in the submucosa .
What are the arrows pointing at?
The kidney provides excellent examples of simple squamous epithelia in the lining of the blood vessels (i.e., endothelial cells), and the internal lining layer of the kidney’s urinary space, surrounding the tuft of capillaries known as glomeruli, called Bowman’s capsule.
What is the arrow pointing at?
There are many profiles of the ductal system of the kidney. Those ductal cells in the cortex provide excellent examples of simple cuboidal epithelium, some with and some without brush borders (microvilli). The arrows delineate simple cuboidal cells in a renal tubule.
What is being bracketed?
The simple columnar epithelium of the gall bladder is delineated between the brackets.
What is this and why?
You have already seen the image of duodenum () in the orientation lab, the enterocytes of which form a simple columnar epithelium, even though the cells may not be identical in nature. The epithelium contains both enterocytes and goblet cells that secrete mucus, and lymphocytes may often be seen migrating between the enterocytes, apparently to sample luminal contents.
What is this and why?
The epithelium of the esophagus is an example of stratified squamous epithelium (non-keratinized). This epithelium resists mechanical abrasion and is found therefore in internal spaces subject to different types of environmental stress. The surface layer is squamous and is refreshed from below as cells are damaged by passage of foodstuffs towards the stomach. This epithelium is also found in the vagina.
What is this and why?
skin is the primary example of stratified squamous epithelium (keratinized). The keratin exterior layer is further protection against environmental insults such as abrasion and dehydration. The surface layer of the epithelium is squamous and is situated on the surface of the cellular layers and below the non-viable keratin layer. The keratin is sloughed off continuously and replaced from below.
What is this and why?
In the same virtual slide of skin are also included profiles of sweat ducts, glands, and hair follicles. These are coiled structures that are interspersed among the follicles. The sweat ducts are more heavily-stained, and are good examples of stratified cuboidal epithelium. Stratified cuboidal and stratified columnar epithelia have only two layers.
What is this and why?
The only place where stratified columnar epithelium is observed in the large, excretory glands of the salivary glands, the parotid, submandibular or sublingual glands. The basal cell layer is cuboidal and the surface cell layer is columnar.
What is this and why?
Nuclei are at various levels of this epithelium but an organized pattern of stratified layers is not apparent. This is a columnar epithelium, but not simple; it is pseudostratified, ciliated.
What is this and why?
Transitional epithelia are characterized as having round polygonal cells in the basal layer with cell layers above which are the same size or larger than the basal cells, i.e., an increase in cell size as you approach the surface which is particularly prominent in the relaxed bladder. Note the nucleus is large and “viable”, in contrast to the stratified squamous epithelium.
What does in situ mean?
In situ refers to neoplasms that have not invaded the basement membrane but have the potential to do so (malignant)
What are umbrella cells?
Umbrella cells are the most superficial cells of the bladder and alter the apical surface via endocytosis and exocytosis. One umbrella cell covers several of the cells underneath and are less conspicuous in the distended bladder. You can see them pretty well here so this tissue was fixed as relaxed. These cells flatten out and look more squamous when the bladder is stretched.
