Pathology Week 17 p16-30

7/30/2019 Pathology Week 17 p16-30

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Myeloid Precursors:

Above (right): Immature granulocytes (left shift). If you have lots of granulocytes (in this case, dont see any blasts),do MPO stain will be positive but wont be helpful because you can tell theyre granulocytes by looking at them. Need todo leukocyte alkaline phosphatase (LAP) test. If normal granulocytes, test will be positive. If CML, LAP will be negative.

CML see more blasts w/nucleoli. LAP is + in leukemoid rxn, neg. in CML.

AML: many blasts. Auer rods = AML. Nothing else makes Auer rods.

Megakaryocytic, erythroid, monocytic series do not make Auer rods. If you see Auer rods, will be AML M2-3-4.

ALL (PAS stain)If you stain lymphoblasts, will bePAS+ and peroxidase negative.


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Above (left): More undifferentiated AMLs. M1 wont make Auer rods, M2 might.Above (middle): M3 promyelocytic; see granules; has 15;17 translocation.Above (right): If you stain w/MPO, granules will be positive (generally M2, M3, M4).

Above: M6 erythroid (RBC). M7 megakaryocytic version.

Case 7. 6 y.o. male with URIs, headache, bone pain and easy bruising;axillary and cervical lymphadenopathy; hepatosplenomegaly.

Young kid w/lots of blasts = ALL. Any time there are 40% blasts, is NOT abenign condition is leukemia.

CBC:Hgb 9MCV 82WBC 92,000 (86% abnormal)Plt 18,000

Above: Sudan Black stain. Will be+ in some AMLs.

Above: Nonspecific esterase. If

you go on to the monocytic series,nonspecific esterase is the bestmarker. These are the ones thatinvolve the gums and oral cavity.

7a. Diagnosis?A. ALLB. AMLC. CLLD. CML


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7b. What test results are expected on a bone marrow aspirate?A. MPO (+), PAS (+)B. MPO (-), PAS (-)C. TdT (+), Precursor B cell (+)D. TdT (-), Precursor T cell (+)E. Sudan black B (+); CD 10 (-)

C. TdT positive and precursor B cell positive.

Case 8. 15 y.o. male with flulike symptoms; axillary and cervicallymphadenopathy; gums are thick and bleeding.

CBC:Hgb 9MCV 90WBC 42,000 (88% abnormal)Plt 22,000

BM Bx results:MPO (-)PAS (-)Sudan Black B (-)

Non-specific esterase (++) markerfor monocytic series.Serum lysozyme 162 (4-15 normal)

8. Diagnosis:A. AML (FAB M1)B. AML (FAB M3)

C. AML (FAB M5)D. ALL (L1)E. Infectious mononucleosis

Lymphomas:

Hodgkin Non-HodgkinRS Cells Low grade- slowly progressive, rare cureOften curable High grade- rapidly progressive; a minority are curableStage important Grade importantFew malignant cells Mostly lymphoma< cell-mediated < humoral

Localized radiation Systemic chemotherapy

One of the lymphomas will be on the glass exam need to recognize Hodgkins, follicular lymphoma, follicularhyperplasia, SLL, and Burkitts. Abdominal lesions will also be on glass slide exam Burkitts, Wilms, or neuroblastoma.

Above (both): Follicular hyperplasia equal in size, rim of blue cells, look in middle see tingible body macrophages.Benign condition due to bacterial infection. Also called adenitis. Bacterial adenitis/lymphoid adenitis = bacterial infectionw/hyperplasia of the follicles.


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Follicular hyperplasia, lymph node. See mantle Follicular hyperplasia, lymph node. Seezone, dark zone, and light zone. See tingible tingible body macrophages, mantle zone, andbody macrophages. lymphoycytes.

Above (both): Follicular lymphoma. Less defined follicles, malignant. No rim of blue cells, no tingible bodymacrophages in the middle. Lymphocytes are monotonous. No variation, no monocytes.

Follicular lymphoma, lymph node. See lymphocytes. SLL/CLL, lymph node. See lymphocyte infiltration.

Above (right): SLL/CLL lots of little round blue cells everywhere. In SLL and CLL, these cells are CD5/CD23+. B celllymphoma that marks w/T cell marker.


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SLL/CLL, spleen see lymphocyte infiltration. SLL/CLL, lymph node. See lymphocytes.

Above (both): Burkitts lymphoma. See tingible body macrophages (stars) and lymphocytes (sky). Have many largemalignant lymphoblasts. Tingible body macrophages are present as in follicular hyperplasia, but in this case, theyaccompany malignant cells. Make sure you can recognize.

Nodular Sclerosis Hodgkin Lymphoma, Lymph Node. Hodgkin Lymphoma. See eosinophils, lymphocytes,See fibrous bands, nodules. and Hodgkin cells.

Need to be able to recognize Hodgkins disease microscopically and descriptively.


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Hodgkin Lymphoma, Spleen. See lymphocytes and Radiograph of Plasma Cell (Multiple) Myeloma.Reed-Sternberg cells. See punched out lesions.

Above (left): In Hodgkins, mainly see benign inflammatory cells eosinophils, plasma cells, lymphocytes, and an

occasional large cell. May see RS classic form. Any time you see a description of mixed inflammatory cells and severallarge atypical cells w/prominent nucleoli = Hodgkins disease.Above (right): Multiple myeloma. Proliferation of plasma cells punched out lesions in the skull. Will also have lightchains in the urine and in the serum.

Plasma cells and bone spicule. Plasma Cell (Multiple) Myeloma, Bone. See plasma cells.

Microbiology/Infectious Disease Review:

Need to know the differencebetween G(+) and G(-).

G(+) have lipoteichoic acid.

G(-) have lipid A andlipopolysaccharides that giverise to toxic shock, etc.


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Most common bacteria that cause infections:

Peptidoglycan: Sugar + cross-linked peptides Osmotic protection Penicillin and cephalosporin inhibit CW synthesis Lysozyme in tears cleaves peptidoglycan

PG is in all bacteria. Is the basis of the mechanism of action of all beta-lactam antibiotics (cephalosporins, penicillin, etc.)When the components of the cell wall mutate, the antibiotics no longer work. Ex: MRSA has MecA mutation that changesbacterial cell wall structure. Beta lactam antibiotics no longer work.

Outer membrane of Gram(-): Lipopolysaccharide (LPS) Lipid A induces IL-1 and TNF; also the ENDOTOXIN component

Polysaccharide (O-antigens of Gram bacteria) Pili for attachment

LPS and Lipid A cause sepsis and shock. In G(+), teochoic acid is most important for attachment to human cells.

Capsule: Polysaccharide except B. anthracis which is D-glutamate Inhibits phagocytosis Used to make vaccines (S. pneumoniae pneumovax; H.influenzae Hib vaccine) Highly antigenic

Some organisms have a capsule, and all the capsules are polysaccharides except for anthrax (capsule is protein).Encapsulated organisms tend to be more resistant but also more antigenic. Almost all the organisms that we havevaccines for have a capsule.


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Glycocalyx: Slimy capsule ofStaphylococcusepidermidis coagulase (-) staphylococci) allows adherence to catheters, for

example (also artificial joints, heart valves, etc.) Polysaccharide extra layer

Spore: Bacillus and Clostridium Resist heat and chemicals Dipicolinic acid

Special Stains: Gram Stain- stains many bacteria but NOT Treponema (Dk Field or silver), the Rickettsia, Mycoplasma,

Chlamydia, Legionella (silver), Mycobacterium (acid-fast), fungi (GMS silver) and viral inclusions

If organisms are cocci firstdo catalase test todifferentiate between Staphand Strep. If catalase +, thendo coagulase test. Ifcoagulase + = Staph aureus.Coagulase is the enzyme that

splits fibrinogen fibrin andcauses a clot.

For G(-) organisms, one ofthe important tests is lactosefermentation. If fermenters,they turn pink on the plates.If not, remain colorless.

If lactose (-), possiblySalmonella, Shigella,

Proteus, Pseudomonas


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Obligate aerobes: Oxygen-dependent ATP M. tuberculosis (lung apex in 2ndary TB), Nocardia, Pseudomonas

Obligate anaerobes: Oxygen is toxic Clostridium, Bacteroides,Actinomyces

One of the key differences between Nocardia and Actinomyces is aerobic vs. anaerobic (both are filamentous).

Intracellular microorganisms: Rickettsia, Chlamydia- energy (ATP) parasites Neisseria Mycobacteriumtuberculosis Salmonella Listeria, Brucella, Francisella, Yersenia Histoplasmacapsulatum

Microorganisms with capsules: Streptococcus pneumoniae, Haemophilus influenzae, Neisseriameningitidis (*Vaccines) Klebsiella IgG2 required for immune response B. anthracis-protein capsule

Cryptococcus neoformans- India Ink or latex agglutination

Above (left): Classic picture ofS. pneumoniae. If you get a sputum sample, will see neutrophils and gram+ diplococci have halo around them (capsule). Pneumococcal pneumonia.Above (right): Capsule of Cryptococcus (encapsulated yeast). Can demonstrate w/India Ink, but Latex agglutination testhas better sensitivity and specificity.

Hemolytic bacteria: Alpha- incomplete hemolysis (turns a little bit green);

Streptococcus pneumoniae (catalase optochin-S);Viridans Group (alpha strep) are optochin-R.

Beta- totally break down RBCs, see cleared areas;

Staphylococcus aureus, Streptococcus pyogenes(Group A), Streptococcus agalactiae (Group B) andListeria (tumbling motility)

Gamma- no hemolysis; Enterococcus

Catalase and Coagulase: Streptococci are catalase Staphylococci are catalase + S. aureus is also coagulase +

Hemolysispatterns:

Catalase +(bubbles):


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Case 1: 20 y.o. female has 103 C fever 2 days after menses. She is hypotensive and hasa rash on her chest.

Desquamating rash may be on trunk, palms, anywhere. Toxic shockUsually due to S. aureus but also can be S. pyogenes.

Methicillin-resistant S. aureus or MRSA: Nosocomial (MecA 1-3) MRSA are resistant to many antibiotics; treat w/Vancomycin Community acquired (MecA4,5) MRSA can be treated with TMP-SMX (Septra -

trimethoprim-sulfamethoxazole)

Staphylococcusepidermidis (CNS): Coagulase-negative (so aka coagulase-negative Staph) Infections in neonates or on indwelling medical devices; adhesion polysaccharide (slime or glycocalyx)

Streptococcuspyogenes: M-protein is antigenic and associatedwith virulence; ASO titer and other lab tests; Bacitracin-S Pyogenic- Pharyngitis, impetigo, cellulitis Toxigenic- TSS, scarlet fever Immunologic- RF and GN Penicillin G Associated w/rheumatic heart disease, post-streptococcal glomerulonephritis

Case 2: 50-y.o. female had a bad strep infection as a child and now has aortic and mitral stenosis

Rheumatic heart disease - mitral valve is mostcommonly involved, aortic 2

nd, both 3

rd.

Beta hemolysis, S. pyogenes (left)

Aschoff body in the heart (right)

Remember that in rheumatic heart disease,there is no bacterial endocarditis in the acutephase. The valves are damaged, but therearent any viable organisms there is an

immunologic reaction. It is only later on thatthey get infected w/other organisms.

Case 2A: Young adult with hx. of rheumatic fever develops mitral valve endocarditis after dental extraction. Themost likely etiology is:

A. Streptococcus pyogenesB. Staphylococcus aureusC. Streptococcus bovisD. Streptococcus mutansE. Streptococcus viridans

There is no such species as E. The alpha strep are all called viridans strep, but streptococcus viridans does not exist.The answer here is D because it is one of the alpha streptococci.

Streptococcus agalactiae: Group B Neonatal sepsis Neonatal meningitis Bacitracin-R; CAMP+ Newborn with seizures- now rare do to treatment of colonized moms

Used to be most common cause of neonatal meningitis. Now we test pregnant women for GBS, so the cases of neonatalmeningitis from GBS have gone way down.


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Streptococcus pneumoniae Encapsulated, Gram+ diplococci, alpha-hemolytic Optochin-S More virulent if pt. is Sickle cell (SS) Disease and/or post

splenectomy spleen is important in defending againstencapsulated microorganisms

Rusty-colored sputum, lobar consolidation, alcoholic

Not in strep viridans group in its own group. Viridans streptococci arealso alpha hemolytic.

Viridans Group (alpha streptococci): Oral flora Optochin-R Endocarditis on damaged valves Splinter hemorrhages (underneath fingernails), Oslers nodes (fingers and toes), Janeway lesions (palms and

soles), Roths spotso All indicate septic emboli from endocarditis

An example is Streptococcus intermedius

This group would cause endocarditis on someone w/a hx of rheumatic heart disease. Two organisms involved originaldamage caused by S. pyogenes and current infection usually caused by alpha streptococci.

Case 5: 20-y.o. man had recurrent pharyngitis as a child now hasfever. Oslers nodes and Janeway lesions are present. Echoshows mitral valve vegetations. Blood cultures grow GPCs

Hx of rheumatic heart disease this patient has endocarditis. Alphahemolytic strep will cause it (usually viridans group).

Figure: A-C. Oslers Nodes; D. Janeway lesion

Oslers nodes big and painfulJaneway lesions small, painless

Both on fingers/toes, palms, and balls of feet.

Clostridium: C. tetani(painful muscle spasms) and C. botulinum (upper body paralysis) C. perfringens- alpha toxin (lecithinase) with myonecrosis/gas gangrene C. difficile- makes cytotoxin that kills enterocytes; pseudomembranous enterocolitis; looks like mushroom on

H&E slide; secondary to ampicillin or clindamycin; **#1 cause of nosocomial diarrhea

Case 6: 30-y.o. construction worker presents with stiff neck and shoulders. He relates earlier difficulty chewinghis food, opening and closing his mouth. LP is performed and is normal. Hands and feet are normal except for anold puncture wound on the bottom of his right foot. = C. tetani(tetanus)

Listeria monocytogenes Gram+ rods; tumbling/umbrella motility Newborn with meningitis shows G+ rod in CSF, cultures show tumbling

motility (under microscope)

Unusual because it is a G+ bacillus. Dairy food, refrigerated items, ice cream(on occasion). Falls head over heels tumbles. In semi-solid media, growslike an umbrella.

Figure: Umbrella motility


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Diphtheria: Corynebacterium diphtheriae Exotoxin inhibits protein synthesis and causes myocarditis Pharyngeal pseudomembrane; Gram+ rods with metachromatic

granules that look like Chinese letters Immigrant girl with sore throat and difficulty breathing; mucous film

on oropharynx

Bacillus anthracis: Malignant pustule Woolsorters disease, gastrointestinal disease, inhalation anthrax Gram+ sporeformer; protein capsule; non-hemolytic Toxin with edema factor and lethal factor both on A subunit Example: Young woman with skin ulcers who works with wool and/or animal hides

Not much lab risk for inhalation in the lab. Safe to work with.

Spores Cutaneous ulcers Causes pneumonia, but cant seespores here.

Bacillus cereus: Spores; aerobic; Gram+ rods Heat-stable toxin (nausea, vomiting) Heat-labile toxin (diarrhea) Example: Young man gets Nausea & frequent Vomiting soon after eating fried rice (6-10 hours)

B. cereus and S. aureus cause food-poisioning in short time preformed toxins.

Actinomyces and Nocardia: Both are Gram+ FILAMENTOUS bacteria which are often

beaded israelii- G+ ANAEROBE causes chronic pneumonia and draining

ulcers and fistulas in the neck (lumpy jaw); also lungs: poordental hygiene; yellow-colored sulfur granules in tissue; NOTacid-fast

Nocardia asteroides; aerobe; weakly acid-fast; pneumonia andbrain abscess; lung and/or brain abscess in transplant pt.

o Nocardia not tradititonal acid-fast stain. Must bemodified acid-fast stain

If you see this, you can tell that it is filamentous G+ bacteria. Needmodified acid-fast stain to tell Actinomyces apart from Nocardia

Red beaded organisms = Nocardia.If we didnt see these, would be Actinomyces.


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Case 7: 45-y.o. male has draining sinuses withpurulent discharge on the left side of his face. He haddental surgery last week. Gram stain shows G+filamentous bacteria. Modified Acid-fast stain isnegative.

Lumpy jaw fromActinomyces filamentous bacteria,non-acid fast.

Figure (left): Microscopically can see sulfur granulesTo naked eye, are yellow.

Figer (right): Gram-positive, filamentousActinomyces.If you look REALLY close (2000x), can see filaments.

Neisseria:N. gonorrhoeae (GC) No capsule No maltose fermentation No vaccine Gonorrhea, septic arthritis and neonatal

conjunctivitis

Ceftriaxone If CT also suspected, add doxy. or azithromycin

N. meningitidis Polysaccharide Capsule Maltose+ Vaccine Meningococcemia, meningitis; Waterhouse-

Friderichsen Syndrome

Penicillin

Haemophilus influenzae: Bacteria with Type B capsule most invasive Chocolate agar; requires X (hematin) AND

V (NAD) factors (see bottom of plate) o Requires heme for growth

Life-threat ceftriaxone Other AmCl (Augmentin), Septra Vaccine between 2 and 18 mos

Case 10: 2-y.o. child living in a commune hasmeningitis. LP shows GNR and growth only onchocolate agar; requires hemin AND NAD;treatment is ceftriaxone.

Case 10-A: 27-year-old AIDS patient has bilateral pneumonia. CD4 count is 250. Gram stain shows gram-negativediplococci.

G(-) diplococci could be Neisseria meningitis orMoraxella catarrhalis (especially in someone w/AIDS). If G(+) diplococci,would be S. pneumo.

Enterobacteriaceae:

Lactose (-): Salmonella- motile; more invasive; 100,000 for

infection Shigella- non-motile; 1-10 for infection (virulent) Proteus- swarmer; UTIs; UREASE+ Pseudomonas

Lactose(+): Klebsiella- capsule; UTI; Lobar Pn.; antibiotic-R coli- UTI; neonatal meningitis; HURS Enterobacter


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Lactose negative will be clear colonies on the selective media. Lactose positive will be pink.Klebsiella G(-) organism, heavily encapsulated. Patients often have reddish/brownish sputum.

Above (left): Selective media. Left lactose positive (E. coli, Klebsiella). Right lactose negative (Shigella, Salmonella)Above (middle): Swarms Proteus. Above (right): Pink slimy half of plate (currant jelly) due to capsule Klebsiella.

Above: If lactosenegative (clear onselective media) andproduces hydrogensulfide on this medium,its Salmonella.

Figure: Causes ofdiarrhea E. coli 0157 associatedw/HUS.Blood and WBCs in stool= invasive!


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C. Difficile: C. difficile mushroom:

In C. difficile, do not see flask see mushroom on top of mucosa.

Amoebic dysentery E. histolytica: Eryhrophagocytosis by amoebae:

H&E Stain of the flask-shaped ulcer. RBCs in macrophages

Other Enterobacteriaceae: Bacteroides fragilis- anaerobe; abdominal infec.;

metronidazole Vibrio cholera- ADP-ribosylates Gs protein with

adenylate cyclase; Lactose-(or slow); non-bloodyricewater stool; doxy. Cholera is non-invasive. Produces toxin.

Treat by replacing fluid (more important to txw/fluid than give antibiotics)

Campylobacter jejuni- growth at 42 C; maybe #1cause of diarrhea; erythromycin

Helicobacter pylori- gastritis, ulcer, MALTlymphoma; urease+; Triple therapy = metro.+tetr.+ Bismuth Hyperplasia of lymphoid tissue MALT

lymphomas (just like in Hashimotos)

TUBERCULOSIS: Caused by M. tuberculosis and less often by M. bovis; (granulomas) M. bovis acquired from milk or cattle with infection via the GI tract; also bladder CA patients Primary TB: mid-lungs areas Secondary TB/Reactivation TB: apical/upper lobes; more necrosis

Above: From AIDS patient w/diarrhea could be Cryptosporidium

(dots coating small intestine malabsorption). Could also be

Giardia, but it would be much bigger and looks like old man w/twobig eyes. Do modified acid-fast stain on stool to demonstrateoocysts (Crypto).

Pathology Week 17 p16-30

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