Exam 3 - POP2

Epiglottis Histology

Elastic cartilage (Blue Arrow) forms core of epiglottis Stratified Squamous Epithelium (Black Arrow) Chondrocytes (Red Arrow)- cells within lacunae (Orange Arrow) inside cartilage

Larynx

False vocal cord (Black Arrow) - upper fold of the larynx is covered by pseudostratified columnar epithelium (Yellow Bracket) •Cilia (Blue Arrow) •Goblet cells (Red Arrow)- secrete mucus

Filiform Papillae

Filiform papillae are cone-shaped and highly keratinized. They do not contain taste buds.

Foliate Papillae

Foliate papillae are square-shaped, non-keratinized, and contain numerous lateral taste buds. Many foliate papillae are found adjacent to each other in parallel rows separated by prominent indentations.

Fungiform Papillae

Fungiform papillae are mushroom-shaped and often have taste buds on their dorsal surface.

IHC Stain w/ Antibody to Calcitonin - C Cells

Immunohistochemical stain with antibody to calcitonin identifies the parafollicular cells. Gives rise to medullary cancer

Intercalated Duct

Intercalated ducts have a light-staining, simple cuboidal epithelium and small lumen. In the pancreas, they directly drain serous acini and empty into intralobular ducts. They secrete bicarbonate ions that help neutralize acidic chyme in the intestines.

Interlobular Duct

Interlobular ducts reside in the connective tissue that separates salivary gland lobules. They have a large lumen. Depending on their size, they have a simple columnar, stratified columnar, or stratified cuboidal epithelium. Many striated ducts drain into an interlobular duct.

Mixed Acinus

Mixed acini are composed of basophilic serous cells and poorly-staining mucous cells. Often, they contain a serous demilune, which is a histological artifact where the serous cells appear to form a moon-shaped cap around the mucous cells.

Mucous Acinus

Mucous acini have a poorly-staining cytoplasm because mucus is a carbohydrate-rich substance that does not attract hematoxylin or eosin. The cells have elongated, basal nuclei and often the lumen cannot be seen.

Myoepithelial Cells

Myoepithelial cells are specialized contractile that have a thin, elongated nucleus and are found at the periphery of an acinus. They contract upon hormonal or nervous stimulation to expel secretory products from acinar cells into an intercalated duct.

Ventral Surface of Tongue

Non-keratinized stratified squamous epithelium

Palatine Tonsil Histology

Non-keratinized stratified squamous epithelium (Blue Arrow) Lymph Nodules (Yellow Arrow) - spherical aggregations of lymphocytes that usually have germinal centers Crypts (Red Arrow) - infoldings of epithelium into the underlying connective tissue

Nasopharynx Histology

ciliated pseudostratified columnar epithelium

TNM for Oropharynx and Hypopharynx +HPV

p16 stains for HPV +HPV has a good prognosis

Pancreas

+12-15 cm J-shaped retroperitoneal organ + Thin overlying capsule of connective tissue +Septa extend to cover vessels and lobules +Acini are surrounded by basal lamina with thin sheets of reticulin fibers +Pancreatic islets (islets of Langerhans) are endocrine clusters found surrounded by acini

Bile Canaliculi and Ducts of Herring

+Bile canaliculi start at the apical surfaces of hepatocytes and bile flows towards the portal triad (opposite blood flow) +Canaliculi empty into the canals of Hering - These simple cuboidal cells are called cholangiocytes +The canals of Hering then merge with the bile ductules - Bile ductules are lined with columnar cholangiocytes +Bile ductules gradually merge to form the right and left hepatic ducts

Pancreatic Endocrine Functions

+Endocrine function - found throughout the pancreas are pancreatic islets (Islets of Langerhans) with at least 5 types of cells that secrete their own hormones. These cells make up ~ 1-5% of the pancreas. •Alpha cells - glucagon (30%) •Beta cells - Insulin (50-70%) •Delta cells - somatostatin •Epsilon* - Ghrelin •F cells - Pancreatic Polypeptide (PP)

Sudan IV/ Oil Red O

+Identifies hepatic steatosis - Only done with FS +Fat contained in hepatocytes turn red

Liver Tumors

+Most common benign liver tumor - hemangioma +Most common primary malignant tumor - hepatocellular carcinoma

Gallbladder Neoplasms (rare)

+Most common benign tumor - adenomas +Most common pseudotumor - cholesterol polyps +Most common malignant tumor - adenocarcinoma (85%)

Gallbladder Histology

+Mucosa - lined with simple columnar epithelium with microvilli and lamina propria +A thin muscularis propria - oriented in several directions +Adventitia and serosal covering +adventitia on the area attached to the liver +Serosa on the remaining surface +The gallbladder does NOT contain a muscularis mucosa or submucosa

Rokitansky-Aschoff Sinuses

+Outpouching of gallbladder mucosa that penetrates the muscle wall (herniations) due to chronic cholecystitis. +They occur with wall hyperplasia and thickening

PAS with Diastase

+PASD helps in the assessment of alpha-1-antitrypsin deficiency - highlights accumulation of alpha-1AT in hepatocytes +Stains lysosomes in Kupffer cells

Space of Disse and Stellate Cell (Ito)

+Perisinusoidal space between the endothelium and the cords +Contains reticulin fibers - to support hepatocytes and endothelium +Fenestrations between endothelial cells allow for free flow of plasma +Hepatocytes extend microvilli into the space - increases absorption surface +Ito cells are found in space of Disse - store vitamin A and other fat soluble vitamins. Produce ECM and cytokines to help regulate Kupffer cells - Can become myofibroblasts after liver injury +Loss of this space in liver disease leads to decreased uptake of nutrients and release of waste by hepatocytes

Iron Stain

+Perl's iron (Prussian blue) - detects iron +Iron is stored in hepatocytes - soluble form (ferritin) and insoluble form (hemosiderin) +In hemochromatosis - iron accumulates in the cytoplasm of hepatocytes +In secondary iron overload - iron accumulates in Kupffer cells

Kupffer Cells

+Resident macrophages of the liver +Provide innate immunity +Found in the sinusoids +Removal of effete erythrocytes

Reticulin

+Reticulin fibers (collagen III) provide support and are prominent in liver, spleen and kidney +In liver, it highlights the space of Disse (Ito cells produce reticulin fibers), hepatocyte loss, hyperplasia and tumors

Liver

+The largest gland in the body +It's an exocrine and endocrine organ +Exocrine - bile +Endocrine - insulin-like growth factor, angiotensinogen, thrombopoietin and hepcidin +Metabolizes carbs, fats and proteins +Detoxification - drugs and alcohol +Storage - glycogen and vitamins + production of heparin and other anticoagulants +Volume reservoir for blood +Catabolism of hemoglobin from old RBCs

Pancreas Histology

+The lobules contain secretory acini surrounded by basal lamina supported by reticular fibers +Pancreatic islands (islets of Langerhans) - clusters of endocrine cells between acini (5%) Acinar cells - polygonal to pyramidal with basophilic cytoplasm and basally located nuclei Intercalated ducts (smallest ducts) to larger collecting ducts - simple cuboidal cells to columnar

Pancreatic Exocrine Functions

+The pancreas is a heterocrine or mixed gland. It has exocrine and paracrine functions. +Exocrine function - aids in digestion. The acinar cells secrete mucin and digestive enzymes (lipase, protease, amylase). +The cells lining the ducts secrete bicarbonate to neutralize stomach acid. Mucin + digestive enzymes + bicarbonate = pancreatic juice. - Pancreatic juice enters the duodenum though the major (and minor) duodenal papilla +Secreted as inactive zymogens +Cholecystokinin (CKK) stimulates enzyme secretion by acinar cells

Liver Dual Blood Supply

+The portal vein brings nutrient rich blood (intestines, stomach and spleen) - 75% +The hepatic artery brings oxygenated blood from the aorta - 25% - These two sources mix together in the hepatic sinusoids before leaving the liver through the hepatic veins

Liver Epithelium

+Thin connective tissue capsule (Glisson's capsule) +Overlying serosa (simple squamous cells) +Interlobular spaces: - Support blood vessels and bile ducts - Reticulin fibers (collagen III)

Rhodanine

+Used to look for the accumulation of cooper within hepatocytes +Wilson's disease

Serous Demilune

A serous demilune is a histological artifact in a mixed acinus where the serous cells appear to form a moon-shaped cap around the mucous cells.

Trachea Full Cross Section

A thick, C-shaped ring of tracheal (hyaline) cartilage is found underneath the submucosa in the trachea. Hyaline cartilage is distinguishably basophilic. Assessing the appearance of hyaline cartilage in different respiratory passages is a key way to distinguish them. The trachea is surrounded by a C-shaped ring, bronchi are surrounded by patches of hyaline cartilage, and bronchioles are not surrounded by any cartilage.

Alveoli

Alveolar ducts are passageways through alveoli that are lined by simple squamous epithelia. Also, they have underlying smooth muscle and minimal connective tissue. Having a thin wall allows the lung to best utilize space for gas exchange between alveoli and capillaries. Alveolar ducts empty into alveolar sacs. These small sacs contain many alveoli and are a primary site of gas exchange.

Bile Ductules

Bile ductules are the vessels within portal triads that carry bile produced by hepatocytes out of the liver. They have a simple cuboidal epithelium with prominent nuclei. While they are normally seen in cross-section with round lumens, it is occasionally seen longitudinally due to the angle of cut.

TNM Liver

CPT code for partial liver resection - 88307

Liver Histology pt2

Central venules are the vessels at the center of classic liver lobules. They are the vessels through which blood exits the liver. Hepatic sinusoids are discontinuous capillaries that travel between rows of anastomosing hepatocytes. They carry mixed blood from the portal triad and drain into a central venule.

Centroacinar Cell

Centroacinar cells are light-staining cells found at the center of a serous acinus in the pancreas. They represent an extension of an intercalated duct into a pancreatic acinus. We know this is the pancreas by the presence of an Islet of Langerhans, which is a round, light-staining cluster of cells.

Parathyroid Histology

Chief cells constitute over 95% of the parathyroid gland. They have a small, dark nucleus and little cytoplasm. They secrete parathyroid hormone, which acts to increase blood calcium. We know this is the parathyroid gland because oxyphil cells (larger cells with a distinct, eosinophilic cytoplasm) are scattered amongst the chief cells. Oxyphil cells are found interspersed amongst chief cells in the parathyroid gland. They have a distinctly eosinophilic cytoplasm due to their abundant mitochondria. Normal Weight: 35-40 milligrams 25-40% of parathyroid gland is composed of adipose tissue

Pars Distalis Histology

Chromphobes are located in the pars distalis (anterior lobe of the pituitary gland). They stain poorly with H&E because their cytoplasm does not contain any hormones. An anterior pituitary acidophil is a type of chromophil that stains pinkish-red with H&E. There are two types of acidophils: somatotrophs secrete GH and mammotrophs secrete prolactin. Unless special techniques are used, the different types of acidophils cannot be distinguished from each other. An anterior pituitary basophil is a type of chromophil that stains bluish-purple with H&E. There are three types of basophils: corticotrophs secrete ACTH, thyrotrophs secrete TSH, and gonadotrophs secrete FSH and LH. Unless special techniques are used, the different types of basophils cannot be distinguished from each other.

Circumvallate Papillae

Circumvallate papillae are the largest and least numerous (humans only have 8-12) lingual papillae. They are dome-shaped, have many lateral taste buds, and are surrounded by a moat-like invagination. Often, circumvallate papillae can be seen macroscopically. They are organized in a V-shape at the back of the tongue.

Club Cell

Club cells are found in respiratory and terminal bronchioles. They are interspersed amongst the simple cuboidal epithelial cells but are round, non-ciliated, and larger than them. They secrete surfactant-like proteins.

Intrapulmonary Bronchi

Intrapulmonary bronchi are surrounded by lung tissue (alveoli). At low magnification, patches of hyaline cartilage are seen underneath their submucosae. Bronchi do not have a trachealis muscle. Instead, they are surrounded by a circumferential ring of smooth muscle. This smooth muscle is important during exhalation as it contracts to help remove air from the lungs. While hard to appreciate at low magnification, smooth muscle cells are not striated and have a centrally located, corkscrew nucleus. BALT (bronchus-associated lymphoid tissue) is an aggregation of lymphocytes found within the lamina propria of bronchi. BALT mounts local immune responses against antigens present in the airway. The submucosa is the layer of dense irregular connective tissue (DICT) underneath the mucosa in the bronchi. DICT contains type I collagen fibers that are densely packed and randomly arranged. Submucosal glands are scattered throughout the DICT in the submucosa.

Trachea Histology

Lamina propria refers to the loose connective tissue found immediately underneath mucus epithelial linings. Respiratory epithelium is considered a mucus epithelial lining because it contains mucus-secreting goblet cells. Lymphocytes are common in the lamina propria and function to mount an immune response against inhaled foreign particles. They migrate here from the blood. The submucosa is the layer of dense irregular connective tissue located underneath the mucosa. In the trachea, the submucosa contains submucosal glands. A thick, C-shaped ring of tracheal (hyaline) cartilage is found underneath the submucosa in the trachea. Hyaline cartilage is distinguishably basophilic and contains chondrocytes located in lacunae. Note that this image is at a medium magnification and we are unable to see the entire C-shape of the cartilage ring.

Identify the strucutres

Letter B indicates a classic liver lobule, which describes the organization of the liver based on blood drainage. Classic lobules are hexagonal shaped with a central venule in the middle and a portal triad at each of the vertices. Blood enters the liver at the portal triads and exits via central venules. Letter C indicates a liver acinus, which is split into three zones based on proximity to the blood supply. Zone 1 is the hepatocytes closest to a portal triad that receives oxygenated blood first. Zone 2 is an intermediate zone. Zone 3 is the hepatocytes closest to a central venule that receives oxygenated blood last. Letter D indicates a portal lobule, which describes the organization of the liver based on bile drainage. Portal lobules are triangular shaped with a portal triad in the middle and a central venule at each of the vertices. Bile is produced by hepatocytes and travels in bile canaliculi towards portal triads where it exits the liver via bile ductules.

Neck Dissection

Level I : Submental and submandibular lymph nodes SUBMANDIBULAR GLAND IS IN LEVEL 1B! Level II: Upper jugular lymph nodes Level III: Mid jugular lymph nodes Level IV: Lower jugular lymph nodes Level V: Posterior triangle lymph nodes Level VI: Anterior Compartment (Superior to Sternal Notch) Level VII: Parasternal (superior) lymph nodes Radical Neck Dissection (Standard) •Cervical LNs, SCM, Internal Jugular Vein, Spinal Accessory Nerve (CN 11), Submandibular Gland, (possibly tail of parotid) Modified Radical Neck Dissection •Does NOT include SCM, Spinal Accessory Nerve, or Int. Jugular Vein Extended Radical Neck Dissection •INCLUDES Retropharyngeal LNs, Regional (Partial, Selective) •INCLUDES only LNs at first metastatic station

Olfactory Epithelium

Olfactory epithelium is a type of pseudostratified columnar epithelium found in the nasal cavity. It contains support cells that secrete odorant-binding protein and odorant receptor cells, however, these cannot be differentiated histologically. In the submucosa, mucus-secreting Bowman's glands can be seen. Often, olfactory fila - branches of the olfactory nerve, can also be seen underneath the epithelium. Olfactory epithelium does not contain Goblet cells.

Nasal Cavity

Olfactory fila, branches of the olfactory nerve, are located in the submucosa underneath olfactory epithelia. Olfactory receptor cells bind odorant molecules and transmit a signal to the olfactory nerve, providing our ability to smell. Due to the presence of myelin, peripheral nerves stain lightly. Bowman's glands are seromucous glands found in the submucosa underneath olfactory epithelia. Each gland contains several acini, which are round collections of cells with a central lumen. They secrete both proteins and mucus, which gives their cytoplasm regions of basophilia and regions that stain poorly in H&E.

Larynx Histology

Pink: Epiglottis Green: False Vocal Cord Yellow: True Vocal Cord Black: Thyroid (Hyaline) Cartilage Red: Ventricle Blue: Vocal Ligament (Dense Irregular Connective Tissue with Elastic Fibers) Orange: Vocalis muscle

Pars Nervosa

Pituicytes are the glial cells found in the pars nervosa (posterior lobe of the pituitary gland). They have small, dark nuclei and support the storage and release of neurohypophyseal hormones. We know this tissue is the pars nervosa because there are Herring bodies. These are small, homogeneously eosinophilic structures where oxytocin (from the paraventricular nucleus) and ADH (from the supraoptic nucleus) are temporarily stored. Herring bodies are small, homogeneously eosinophilic structures in the pars nervosa. They represent the terminal ends of axons where hormones are temporarily stored. Specifically, they store oxytocin produced in the paraventricular nucleus and ADH (vasopressin) produced in the supraoptic nucleus.

Salivary Gland Tumors

Pleomorphic Adenoma : slow growing, painless, well circumscribed mass •Most common salivary gland tumor Warthin Tumor (aka papillary cystadenoma lymphomatosum): almost exclusively in parotid gland Mucoepidermoid Carcinoma: •Most common malignant salivary gland (2nd most common overall) •Well circumscribed with gray-white, mucin filled cysts

Portal Triad

Portal triads are the structures found at the vertices of classic liver lobules. They are composed of a hepatic arteriole, portal venule, and bile ductule. Hepatic arterioles are the vessels within portal triads that supply oxygen-rich blood to the liver. They have a round lumen and a tunica media that is 1-3 smooth muscle cell layers thick. Supply the liver with oxygen rich blood. Portal venules are the vessels within portal triads that supply the liver with nutrient-rich blood from the GI tract. They have a large, irregular lumen and very thin tunica media and endothelium. Supply the liver with nutrient rich, oxygen poor-blood. Bile ductules are the vessels within portal triads that carry bile produced by hepatocytes out of the liver. They have a round lumen and simple cuboidal epithelium with prominent nuclei. Transports bile out of the liver.

Respiratory Bronchioles

Respiratory bronchioles are the first respiratory passage in the respiratory system. They are lined with simple cuboidal epithelia. They are not surrounded by any cartilage and do not contain submucosal glands or goblet cells. They can be distinguished from terminal bronchioles because they will have 1-2 alveoli budding out from their wall.

Respiratory Epithelium

Respiratory epithelium (pseudostratified columnar epithelium with cilia and goblet cells) is found lining the majority of the conductive passages in the respiratory system. It has the appearance of being stratified (i.e, nuclei appear at different levels but all cells are in contact with the basement membrane). Cilia can be seen at the apical surface of the cell and poor-staining, mucus-secreting goblet cells are interspersed throughout the epithelium.

Serous Acinus

Serous acinar cells have a basophilic cytoplasm and a round, basal nucleus. Their cytoplasm is basophilic because it contains a lot of ribosomes that make the proteins that the parotid gland secretes.

Striated Ducts

Striated ducts have a simple columnar epithelium, centrally located nuclei, and a prominent lumen. They are very eosinophilic and have striations due to their prominent basal plasma membrane folds. They secrete bicarbonate into the salivary fluid, which buffers the pH in the oral cavity.

Taste Bud

Taste Bud (Blue Arrow) •Found in epithelium •Consists of taste receptor cells (aka gustatory cells) Taste Pore (Red Arrow) •Circular opening at apex

Terminal Bronchioles

Terminal bronchioles do not have any cartilage surrounding them, nor do they have submucosal glands or goblet cells. They are lined with simple cuboidal epithelia that contain club cells.

Alveolar Septum

The alveolar septum is made up of type I pneumocytes, endothelial cells, and their respective basement membranes. This forms the air-blood barrier. However, specific cell boundaries are beyond the resolution of light microscopy, so we cannot accurately differentiate between endothelial cells and type I pneumocytes.

Trachealis

The trachealis is the smooth muscle found posteriorly in the trachea. It connects the free ends of the tracheal (hyaline) cartilage ring. It lies directly adjacent to the esophagus and imparts flexibility when swallowing a large bolus of food. Smooth muscle cells are not striated and have a centrally located, corkscrew nucleus.

Thyroid Histology

The colloid is a gel-like mass in the lumen of thyroid follicles. It largely acts as a reservoir for thyroglobulin. This is an immature form of the thyroid hormones T3 and T4 secreted by the surrounding follicular cells. Colloid also contains iodine, and the iodination of thyroglobulin is an important step in the formation of T3 and T4. - calcium oxalate crystals in Parafollicular cells "C Cells" are found in between thyroid follicles. They are larger than follicular cells and have a light-staining cytoplasm and euchromatic nucleus. They produce calcitonin, a hormone that acts to reduce blood calcium. Thyroid follicles contain a simple cuboidal layer of follicular cells. These cells release thyroglobulin, an immature form of T3 and T4, into the colloid they surround. When stimulated by TSH, they reabsorb thyroglobulin to complete the maturation process and then release T3 and T4 into the bloodstream.

Serous Acinar Cell

The exocrine pancreas is made up of serous acini that secrete digestive enzymes. Serous acinar cells have a basophilic base that represents their extensive RER network and an eosinophilic apex where zymogen granules are stored. They produce trypsinogen, amylase, and lipase. We know this is the pancreas by the presence of an Islet of Langerhans, which is a round, light-staining cluster of cells. This cell is stimulated by cholecystokinin (CCK) to secrete trypsinogen, lipase, and amylase. CCK is secreted by enteroendocrine cells in the intestines. We know this is the pancreas by the presence of an Islet of Langerhans, which is a round, light-staining cluster of cells.

Hepatocytes

The functional cells of the liver. They are arranged in anastomosing rows that radiate outward from a central venule. In H&E, they have a moth-eaten cytoplasm because they store glycogen. They also have a euchromatic nucleus because they are metabolically active. The indicated cell is a hepatocyte and two of the hormones produced by the endocrine pancreas are insulin and glucagon. Insulin stimulates hepatocytes to store glucose intracellularly as glycogen. Contrarily, glucagon stimulates hepatocytes to break down glycogen and release glucose into the bloodstream. +Large cuboidal to polygonal cells with 1-2 nuclei and high incidence of polyploidy (50%) +Synthesis and secretion of major plasma proteins (albumins, fibrinogen, apolipoproteins, transferrin, etc) +Gluconeogenesis +Detoxification +Production of urea removed from blood in kidneys +Storage of glucose and triglycerides +Storage of vitamin A and other fat soluble vitamins +Storage of Iron (in complexes with ferritin)

Gallbladder Histology pt2

The gallbladder has a simple columnar epithelium with mucosal folds and can be confused with sections of the GI tract. However, it does not have a muscularis mucosa or submucosa. Instead, it has a large, randomly-oriented muscularis externa. Contraction of the muscularis externa results in the emptying of the gallbladder. Cholecystokinin (CCK) stimulates the muscularis externa to contract and expel luminal contents. CCK is produced by enteroendocrine cells in the intestines. These cells also produce secretin.

Liver Histology

The liver is organized into hexagonal lobules with a central venule in the middle and a portal triad at each of the vertices. The functional cells of the liver are hepatocytes, which are organized into anastomosing rows that radiate outward from the central venules.

Parotid Gland

The parotid gland is largely composed of basophilic serous acini. •Serous cells - secrete protein-rich fluid •Mucous cells - secrete mucin •Mixed Gland...BUT almost entirely serous •Secrete α-amylase and proline-rich proteins Branched acinar glands and lots of adipose tissue

Pars Intermedia

The pars intermedia is located in between the pars nervosa and pars distalis. It is quite thin and contains colloid-filled cysts. These cysts are embryological remnants of Rathke's pouch, a structure that proliferates during development to help form the pituitary gland.

Pineal Gland Histology

The pineal gland is a small endocrine gland in the center of our brain. It contains euchromatic pinealocytes that synthesize melatonin, a hormone responsible for regulating our sleep-wake cycle. It also contains brain sand (corpora arenacea), calcified concretions formed as a byproduct of melatonin secretion. Brain sand often appears black in color.

Gallbladder

The release of bile is stimulated by the presence of dietary fats in the small intestine where it acts as a surfactant to emulsify and digest lipids from food. +The mucosal folds allow for the gallbladder to expand +The mucosa actively pumps Na+ that is followed by passive movement of water +Secretion of the stored bile is induced by cholecystokinin (CCK) from the neuroendocrine cells of the duodenum

Sublingual Gland

The sublingual gland is largely composed of mucous acini. Mucous acinar cells have a poorly-staining cytoplasm because mucus is a carbohydrate-rich substance that does not attract hematoxylin or eosin.

Submandibular Gland

The submandibular gland contains mixed acini, which are composed of basophilic serous cells and poorly-staining mucous cells. The mixed acini often contain serous demilunes, which are histological artifacts where the serous cells appear to form a moon-shaped cap around the mucous cells. Mixed Gland •Serous Acini > Mucous Acini •Notice that there are more darker staining cells than paler staining cells •Mostly serous Serous Cells (dark stain) Mucous (light stain) Serous Demilunes (Crescent shaped cluster of Serous Cells) Secrete α-amylase, proline-rich proteins AND lysozyme Branched tubuloacinar glands

Trachea

The trachea is the largest conducting passage in the respiratory system. At high magnification, it is easily identifiable by the thick band of hyaline cartilage under the submucosa. It has a mucosa containing respiratory epithelium and a lamina propria and a submucosa containing submucosal glands and dense irregular connective tissue.

Verhoeff Stain

Verhoeff stain: Used to demonstrate elastic fibers Elastic fibers show up black within the cartilage matrix of the elastic cartilage

Lips Histology

Vermilion Border (V): The red area of the lips •Thin lightly keratinized skin External surface of the lip (S): Keratinized stratified squamous epithelium Oral Mucosa (O): Nonkeratinized stratified squamous epithelium

Von Ebner's glands

Von Ebner's glands are the only gland found within the tongue epithelium. The indicated gland is found within a foliate papilla, which is square-shaped, contains lateral taste buds, and is organized in parallel rows. Von Ebner's glands are basophilic serous glands that help solubilize food so that it can better come into contact with taste buds. Note that they are also found nearby circumvallate papillae.

Tonsils

Waldeyer's Ring 1.Pharyngeal tonsils (aka "adenoids") 2.Tubal tonsils - Surrounds opening of Eustachian tube 3.Palatine tonsils - (aka "the tonsils") 4.Lingual tonsils - located at base of tongue The tonsils are the #1 most common site of occult squamous cell carcinoma •This is why some places will have you submit the tonsils entirely if the patient is above a certain age.

Dorsal Surface of Tongue

Yellow: Filiform papillae Highly keratinized & no taste buds Red: Fungiform papillae Thin keratin layer & dorsal taste buds

Types of Pancreatic Tumors

•Adenocarcinoma (90%) - from the lining of the ducts (ductal adenocarcinoma). - Most arise in the head region - < 5% 5-year survival - Risk factors - alcohol, smoking, hereditary mutations/syndromes, pancreatitis •Cystic neoplasms - benign or malignant. Can contain fluid, mucin, etc •Pancreatic neuroendocrine tumors - from Islets of Langerhans cells, can be benign or malignant and can secrete hormones. - Associated with hereditary syndromes (20%) +Multiple Endocrine Neoplasia syndrome (MEN1 and MEN4) +Von Hippel-Lindau +Neurofibromatosis type 1 +Tuberous sclerosis +Etc

Oral Cavity Cancers

•Can occur in any part of the mouth - Lips, lateral tongue, floor of mouth •Most common cancer is squamous cell carcinoma •Risk Factors: - Smoking - Chewing tobacco - Alcohol - Older (>50) Males

Carcinoma of Larynx

•Most common = squamous cell carcinoma •Risk Factors: •Male chronic smokers •Alcohol Pre-epiglottic space is the most common site for tumor invasion

Pharynx Specimens

•Nearly all are for squamous cell carcinoma •Usually in conjunction with other resections - Nasopharynx - resected with maxillectomy - Oropharynx - resected with base of tongue/retromolar trigone/palatine tonsil resections - Hypopharynx - resected with laryngectomy (laryngopharyngectomy) •Nasopharyngeal cancer is strongly associated with EBV infection •Oropharyngeal and hypopharyngeal cancer is strongly associated with HPV infection

Tongue Histology

•Non-keratinized stratified squamous epithelium (Blue Arrow) •Bundles of skeletal muscle running in all directions allows tongue to move in any direction

Salivary Gland Neoplasms

•Pleomorphic adenoma is #1 most common salivary gland neoplasm •Mucoepidermoid carcinoma is #1 most common malignant neoplasm and 2nd most common neoplasm