44, 45 - Histological Diagnosis I Flashcards

Question

What stain is this? What is it used for?

Answer 1

Visualize infectious microorganisms

Answer 2

Visualize infectious microorganisms

Answer 3

Alcian blue: This stain is used by pathologist to identify mucoid (mucus-like) substances within cells. For example, this stain can be used to identify mucin (family of glycoproteins with high sialic acid or sulfated polysaccharides) containing goblet cells as part of intestinal metaplasia at the gastroesophageal junction (Barrett’s esophagus) (Figure 1). Using this stain, acid mucins (those seen in intestinal glands) and cartilage are blue, while nuclei appear red, and cell cytoplasm appears pink.

Answer 4

Congo red: This stain is used to detect amyloid protein. However, it is unable to distinguish different types of amyloid proteins (e.g. Lambda light chains in AL amyloid vs. acute phase reactant proteins in AA amyloid). Using this stain, amyloid appears red-pink and takes on an apple-green color upon exposure to polarized light (Figure 2) while nuclei are blue. In the virtual microscopy slide collection, a section of soft tissue is stained with Congo red. Please note the abundant, amorphous, red-pink material throughout the section.

Answer 5

Elastic Stain (Verhoeff-vanGieson): Clinically, this stain can be used to help identify arteries and veins in the setting of vasculitis (inflammation of the vessels). This stain highlights elastic fibers, staining them a blue-black to black color. Nuclei are stained blue/black while collagen is red and other tissues are generally yellow. In the figure below (Figure 3), panels “A” and “B” show low and high power views, respectively, of an artery involved by giant cell arteritis. In “C”, the artery is stained with an elastic stain which helps delineate the elastin fibers within the wall of the vessel (labeled “E”). These fibers are partially disrupted by the vasculitic process (red arrow). In the virtual microscopy slide collection, please examine slide 220, an artery stained with an elastin stain. In this slide, the elastic fibers stain blue while the background tissue stains blue-yellow. Please note the wavy inner elastic lamina layer (closest to the lumen of the vessel).

Answer 6

Iron (colloidal iron): This stain highlights iron deposition in tissues. Clinically, this can be used to evaluate iron stores in the bone marrow or to highlight excess iron deposition in the liver, seen in a condition called hemochromatosis. When this stain is used, ferric iron appears blue, cell nuclei appear red, and cell cytoplasm appears pink. In the virtual microscopy slide collection, there is a slide with a section of liver stained with an iron stain. Please note the extensive collections of iron within the hepatocytes highlighted in blue by the iron stain.

Answer 7

Grocott methenamine-silver nitrate (GMS): This stain is used to highlight infectious organisms within tissues. For example, fungi and Pneumocystis jerovecii appear black in a GMS stain while the background tissue appears green due to a counter stain (Figure 4). In the virtual microscopy slides, a portion of thick skin (either from the palm of the hand or the sole of the foot) has been stained using a GMS stain. Please note that in the most superficial, acellular layers of the epidermis, there are numerous organisms highlighted in black. These are likely fungal elements as part of a fungal infection of the skin.

Answer 8

Masson’s Trichrome stain: The Masson’s trichrome stain is used in pathology to highlight areas of fibrosis, for example, fibrosis seen in the liver in cirrhosis (Figure 6). Using this stain, tissues usually stain one of three colors: collagen stains blue (mature, type I collagen stains dark blue while immature collagen, types 3 and 4, stains light blue); mucin stains green or blue; nuclei stain black; and keratin and the cytoplasm of cells stain red. In the virtual microscopy collection, please focus on the section of colon stained using a trichrome stain and note how different elements of the colon wall stain differently using this stain.

Answer 9

Mucicarmine stain: In pathology, the mucicarmine stain is used to help identify the presence of mucin within cells (Figure 7, right). A mucicarmine stain can also be used to highlight the thick, polysaccharide capsule of the fungus, Cryptococcus (Figure 7, left). Using the mucicarmine stain, both mucin and the cryptococcus polysaccharide capsule appear deep rose to red while nuclei appear black, and background tissue appears blue or yellow. In the virtual microscopy slide collection, there is a slide of small bowel stained with a mucicarmine stain. Please note that the mucin droplets within the goblet cells of the small bowel epithelium are pink while the remaining tissue is yellow, due to the counterstain.

Answer 10

Oil red O: This stain is used by pathologists to highlight fat. This stain requires frozen tissue sections as most fixatives dissolve lipids during tissue processing. Using this stain, fat appears red, and nuclei appear blue (Figure 8). We do not have an example of an oil red o stain for our virtual microscopy slide collection, but an example of this stain is pictured below.

Answer 11

Periodic acid-Schiff reaction (PAS): This stain reacts with complex carbohydrates, staining them a deep red or magenta color. Structures/cells that stain magenta with this stain are considered “PAS positive”. PAS positive structures include mucin within goblet cells of the gastrointestinal and respiratory tracts; basement membranes and brush borders of kidneys, small, and large intestine; cartilage; collagen (somewhat); fungi and glycogen. A PAS stain can also be used with a diastase digestion. Diastase digests glycogen, preventing it from staining. Staining with PAS both with and without diastase can help determine whether or not PAS positive material is glycogen. In a disease called alpha 1 antitrypsin deficiency, PAS positive deposits within the cytoplasm of hepatocytes (liver cells) are diastase resistant, indicating that they are not composed of glycogen (Figure 9). In the virtual microscopy slide collection, there is a slide with a section of liver stained with PAS without diastase digestion. Please note the small, deep pink granules within many of the hepatocytes (cells of the liver). These are PAS positive deposits.

Answer 12

Reticulin stain: This stain is used to stain reticulin fibers that are composed primarily of type III collagen. In the bone marrow, increased reticulin fibers can be associated with some bone marrow disorders such as idiopathic myelofibrosis (Figure 10). Increased reticulin fibers can also be seen in the liver as part of liver fibrosis or veno-occclusive disease. A reticulin stain stains reticulin fibers black, mature collagen (type I) brown, and immature collage (types 3 and 4) black. In the virtual microscopy collection, please look at the slide containing liver tissue stained with a reticulin stain. Note the presence of reticulin fibers (black) along the edges of the hepatic sinusoids (the light, “empty” spaces between the cords of hepatocytes).

Answer 13

Warthin-Starry: This stain is used to highlight certain infectious organisms within tissues including spirochetes (syphilis), helicobacter (H. pylori), and Bartonella henselae (cat scratch fever). Using this stain, the aforementioned organisms stain black while the background tissue stains pale yellow to light brown (Figure 11). Although we do not have an example of this stain in our virtual microscopy collection, please see figure 11, which demonstrates use of this stain for identifying H. pylori in gastric biopsies.

Answer 14

Mucicarmine

Answer 15

Mucicarmine

Answer 16

Mucicarmine

Answer 17

PAS without Diastase

Answer 18

PAS without Diastase

Answer 19

PAS without Diastase

Answer 20

Chromogranin

Answer 21

Chromogranin

Answer 22

ISH - Lambda

Answer 23

ISH - Lambda

44, 45 - Histological Diagnosis I Flashcards

(78 cards)