Forensic Pathology 2 Flashcards
What does inductively coupled plasma-mass spectrometry measure in forensics?
Trace elements, ie selenium
What is gas chromatography primarily used for in forensics?
Low molecular weight volatiles ie ethanol
By which lab instrument is sodium, potassium and lithium measured?
Na and K: ion-selective electrode
Li: colorimetric methods
(Used to be flame photometry)
What does ELISA measure for in forensic lab?
Antibodies or antigens ie HIV testing
What is scanning electron microscopy/energy dispersive xray spectrometry used for?
Gunshot residue on clothing/skin
How is probability of paternity calculated? What is minimum probability of paternity?
1-(1/combined paternity index) x 100%
Minimum: 99% (99.5% in immigration cases)
What would a) osteogenesis imperfecta and b) rickets look like on X-ray?
A) fractures of multiple bones
B) rosary beads (widening/prominences at costochondral junctions)
What natural diseases besides sepsis/clotting issues are abdominal ecchymoses associated with?
Pancreatitis, neuroblastoma
What is a) beta-APP and b) p-tau protein seen in?
A) diffuse Axonal injury
B) CTE
Calcification of vessels in basal ganglia is the cause of what?
Past trauma (which makes it susceptible to more future trauma)
In subdural hemorrhage, when do you start to see a) granulation tissue including fibroblasts & endothelial cells, b) hemosiderin in macrophages
A) 1 week
B) ~few days with Prussian blue
In subdural hemorrhage, when do you start to see a) capillary dilation with perivascular neutrophils, b) true inner (leptomeningeal side) membrane, c) both outer (dural side) and inner membrane with connective tissue & hemosiderin?
a) <24 hrs
B) 2-4 weeks
C) 1-3 months
a) Fracture of proximal humerus with epiphyseal separation and b) epiphyseal separation fractures of distal humerus are common with what situations?
a) child abuse with severe trauma,
b) pulling or twisting of arm (can also be abuse)
What does laceration of labial frenula indicate?
Blunt trauma to face
When can you see retinal hemorrhages in non-traumatic cases?
sepsis, coagulopathy, vacuum-assisted and SVD (but disappear by 1 month)
What is specific within the eye for inflicted head injury?
1: traumatic retinoschisis (tearing of the retina away from its attachments),
#2(not as specific): optic nerve hemorrhage
Microscopically in rib fracture healing, when does a) new cartilage and bone start to form, and b) bony union (callus) start to form?
a) 1 week,
b) 3-6 weeks
Where specifically do inflicted injury posterior rib fractures most commonly occur?
costotransverse process articulation (neck, not head, of rib articulation with spine)
What bony injuries are associated with shaking of small child?
metaphyseal fractures of tibiae, distal femora, and proximal humeri; outer ends of clavicles also suggestive of non-accidental injury
What does fractured bone look like histologically?
“infarcted” appearance: pale staining /dead osteocytes and poorly staining amorphous marrow elements
What type of osteogenesis imperfecta can be confused with pediatric trauma and what are the characteristics?
type IV: osteoporosis, thin cortices, bowing of extremities, wormian bones in skull, multiple rib fractures (NO blue sclerae (that’s type 1))
- all types have type 1 collagen abnormalities
Besides middle meningeal artery, what can epidural hemorrhage be caused by?
1) tear in dural sinus i.e. superior sagittal sinus/transverse sinus (–>hemorrhage in posterior crainial fossa),
2) middle meningeal vein
What head injury is associated with hyperextension injury of the neck?
hinge fracture (blow to chin or forehead causes hyperextension of neck)
Difference between epidural and subdural surfaces histologically
Will see thick-walled middle meningeal arteries on epidural side; will see “roughed up”/torn appearance on epidural side (from evisceration)
What two situations commonly result in ring fractures?
Head impacted from above (forces base of skull down onto spinal column) or descending from height onto feet/buttocks (spinal cord thrust upward onto base of skull)
Besides bridging veins, what can subdural hemorrhage be caused by?
1) dural sinus
2) cerebral cortical arteries/veins
What cerebral injuries involve a) gyri vs b) sulci?
a) cerebral contusions,
b) hypoxic-ischemic lesions and cerebral infarcts
What distinguishes amyloid angiopathy-related intracerebral hemorrhage?
Multiple, in older people, parieto-occipital distribution
Does coup contusion have overlying skull fracture?
NO; if it did it would be called “fracture contusion” instead
What are a) intermediary coup? b) Gliding contusions?
a) deep in brain parenchyma (“in middle” of coup and contrecoup)
b) curvilinear contusions of parasaggital white matter of frontal lobes
What distinguishes remote cerebral contusion from remote cerebral infarct?
Contusions have disrupted cortical surface, infarct does not & is wedge-shaped (vascular distribution)
What is anhydroecgonidine specific for?
Metabolite for crack cocaine
What is dronabinol’s active ingredient?
Delta-9-THC
(So it’s a synthetic cannabinoid BUT an innocuous one)
What fatal chemical compound is in a) household cleaners, b) pesticides?
A) HCl and sulfur —> H2S aka hydrogen sulfide —> thiosulfate
B) AChE inhibitors
How quickly does ethanol metabolize?
15 mg/dL per hour
What are the gross findings fairly specific to diffuse traumatic brain injury (often with MVAs)?
Hemorrhages in the deep long white matter tracts, usually corpus callosum, internal capsules, and superior cerebellar peduncles,
+/- gliding contusions and intermediary coup contusions, +/-
“diffuse vascular injury” (petechiae in white matter of frontal lobe)
What are the microscopic findings of diffuse traumatic brain injury and how much survival time is needed to show it?
dystrophic axons: bulbous, eosinophilic axonal swellings, eventually beaded; >18-24 hrs;
however, b-APP highlights dystrophic axons by 2-3 hrs
How to tell histologically the difference between axonal injury from ischemia and traumatic axonal injury?
ischemia: the injury will have wacy/linear/zigzag distribution on high power
traumatic: will be more scattered/along long axis of axon
What is the histologic difference between red neurons (ischemia) and dark neurons (post-mortem artifact?
dark neurons has densely staining but less “red”, have wavy/corkscrew dendrites (tails of neurons)k, and have interspersing normal-appearing neurons
What are Duret hemorrhages caused by?
cerebral ischemia from increased ICP causing herniations –> reperfusion, aka “secondary brainstem hemorrhages”
What is the difference between respirator brain and persistent vegetative state?
There IS perfusion of the brain in persistent vegetative state, so reactive processes can occur; there is NOT perfusion of brain in respirator brain so it is bascially autolyzing and softening
What is Wallerian degeneration?
chronic changes after spinal cord injury making post-injury areas shrink & look grey (demyelinated)
What toxicology tissue sample is best for testing for a) TCAs, b) volatiles, c)heavy metals?
a) liver,
b) lung, adipose tissue
c) kidney, fingernails/toenails/hair
What is the best toxicology tissue specimen to get in embalmed bodies?
skeletal muscle from BUTTOCK
With what sample should toxicology of GHB be measured and why?
urine - because GHB is produced de novo by the body in blood but not bladder
What is normeperidine and its significance?
metabolite of meperidine (u-receptor agonist, opioid) – is more toxic than its parent drug so it can contribute to death to see high levels of the metabolite
What specific tissue can be studied in dopamine dysfunction conditions (i.e. excited delirium from cocaine)?
fresh brain–> frozen, look at substantia nigra and corpus striatum to include nucleus accumbens
Besides fetal squamous epithelial cells, what can you see in pulmonary arteries of the mother in amniotic fluid embolism?
lanugo, meconium, mucin from fetus’s intestinal tract
What is the most common immediate COD of eclampsia? pre-eclampsia in HELLP?
E: intracerebral hemorrhage,
HELLP: ruptured subcapsular hematoma of liver
maternal deficiency of long chain 3-OH-CoA dehydrogenase, think what?
acute fatty liver of pregnancy (centrilobular microvesicular steatosis, cholestasis, necrosis)
If placental abruption occurs a) minutes to hours vs. b) days after a maternal trauma, what are the most likely causes?
a) the trauma itself / b) maternal HTN, cigarette smoking, cocaine abuse
What kind of skull fracture in delivery of a fetus is most severe, and what is it associated with?
Separation (diastasis) of temporal and occipital bones at lambdoid suture – breech presentation with neck hyperextension
Where is birth-related SDH vs child abuse SDH located in head?
birth-related: posterior fossa/infratentorial
abuse: supratentorial
What is the a) unknown persons database, and b) main DNA databank for ID?
a) National Crime Information Center (NCIC),
b) Combined DNA Index System (CODIS)
Osteology: prominent nasal projection, pinched appearance of nose(anterior), prominent nasal sill (inferior), flat facial profile, V-shaped palatal arcade, Carabelli’s cusp on maxillary molar, inion hook on occipital protuberance: what race?
White
Osteology: Flat facial profile, sloped and flat nasal root, broadly spaced orbits, Prominent zygomatic bones that project laterally and have supernumerary sutures, half-circle/elliptical palatal arcade, shovel-shaped incisors, wormian ossicles- what race?
Asian
Osteology: flat and wide nasal region with nasal gutter, prognathism, rectangular palatal arcade, simple/straight cranial sutures, post-bregmatic (at union of coronal and Sagittal sutures) depression: what race?
Black
Osteology: What are the 3 most important feature of the innominate for determining sex?
- Greater sciatic notch (thumb test)
- Suprapubic angle (hand at right angle, if thumb easily touches ischial ramus it’s female)
- Width ratio of pubis to ischial ramus (F 2:1, M 1:1)
Osteology: what feature is associated in the innominate with previous childbirth?
Marked dorsal pitting
Osteology: what are 3 differing skull features of male vs females?
- Males with wider and longer projections of their mastoid processes
- Female frontal bone with one central prominence, males with two
- Supraorbital tori/prominence in males
Osteology: What is the most reliable bony age indicator for a) adults, b) kids?
A) pubic symphysis (Todd stage 1-poodle/ stage 5/6 fried chicken leg to boulder / stage 10 flattened beetle)
B) long bones
Osteology: what is the first epiphysis to close in child long bone remains?
Greater tubercle of humerus (2-4 years)
What are the first primary (deciduous) teeth to erupt and at what age? what age do the final (second molar) primary/deciduous teeth erupt?
1) Mandibular central incisors, 6 months
2) maxillary second molars at 24 months
What are X-ray and autopsy findings of inhalational anthrax?
X-ray: widened mediastinum, pleural effusions
Autopsy: serosanguinous pleural effusions, hemorrhagic/necrotic mediastinal LNs, hemorrhagic meningitis
What are the autopsy findings of pneumonic vs bubonic plague, and what is the organism?
Yersinia pestis (gram -)
Pneumonic: pneumonia, resp failure, extensive ecchymoses/DIC
Bubonic: skin pustules, hemorrhagic LNs
What are general findings in viral hemorrhagic fever, and what is a main finding in yellow fever that differentiates it?
Diffuse petechiae/ecchymoses, necrosis of liver/lymph nodes with viral inclusions, DAD
Yellow fever: MIDZONAL hepatic necrosis
What are the organism/characteristics for Tularemia and autopsy findings?
Francisella, nonmotile gram (-) coccobacillus
Necrotizing granulomatous lymphadenitis, typhoidal type has systemic organ necrosis
What is the mechanism of action of nerve agents (tabun, sarin, soman, VX) and what is their antidote?
Acetylcholinesterase inhibition (cholinergic symptoms)
Treatment: atropine, pralidoxime, diazepam
What does Lewisite chemical agent smell like, what does it cause, and what is the antidote?
Fruity odor, causes tissue necrosis and increased capillary permeability leading to shock
Treatment: BAL dimercaprol
Allele duplication of a) CYP2D6 and b) CYP3A causes toxicity via metabolizing which drug?
A) codeine (increased metabolism to morphine)
B) benzos
In the vaginal canal, long do you see a) motile sperm with tails (and what IHC can you use), b) non-motile sperm with tails, b) sperm heads only?
A) <12 hours, acid phosphatase and p30
B) 18-24 hrs
C) 1-5 days
What two things should you think about with rigidity of the body including face / spasmodic contractions of the body?
Tetanus or strychnine poisoning
What is seen with measles vs rabies encephalitis?
Measles: eosinophilic Nuclear inclusions (N M; Warthin-Finkeldey bodies)
Rabies: neurons and glial cells with CYTOPLASMIC eosinophilic inclusions(negri bodies)
What is a) perivascular lymphocytic cuffing and b) perivascular giant cells seen in within CNS?
A) viral encephalitis, acute poliomyelitis, MS (also w plasma cells)
B) AIDS (in white matter), fungal infections
Where in the brain does a) toxoplasma and b) herpes encephalitis typically infect and cause cystic degeneration/necrosis?
A) lateral ventricles
B) temporal lobes
What, besides hypocoagulative states, can cause petechial hemorrhages of the brain?
Fat embolism, diffuse brain injury, hypertensive encephalopathy, cerebral malaria
Histologically, what areas of the brain do you see hypoxia (necrosis) in?
Neocortex (layers 3,5,6) in sulci>gyri,
Hippocampus Ca1&4, purjinke cells of cerebellum
Where do you see bilateral hemorrhagic necrosis of a) globus pallidus+/- basal ganglia, b) putamen?
A) carbon monoxide poisoning (carbon=earth=globe) (can also be seen with heroin, barbs, insulin OD)
B) methanol intoxication
Multiple Yellow-brown (acute) or grey-brown (chronic) lesions in white matter around lateral ventricles and third ventricles: what disease?
Multiple sclerosis (areas of demyelination)
What do you see grossly and histologically in Parkinsons?
Grossly: depigmentation of substantia nigra and locus ceruleus of pons
Histo: neuronal loss with depigmentation, Neuromelanin within macrophages, LEWY BODIES within cytoplasm of residual neurons (ubiquitin+)
What 3 findings are seen with Zellweger’s syndrome?
Peroxisomal disorder with:
Hepatic cirrhosis, grey matter heterotopias, and polymicrogyria
What gross and histological findings are seen with Leigh’s disease?
Mitochondrial disorder with Symmetrical discolored lesions in basal ganglia
Demyelination, macrophage infiltration, vascular proliferation
What CNS changes do you see in a) Wernicke’s encephalopathy, b) vitamin B12 deficiency?
A) aka thiamine (but B1) deficiency: lesions in mamillary bodies, hypothalamus: hemorrhagic if acute and demyelinated if chronic
B) demyelinization (pallor) and lipid laden macrophages in lateral corticospinal tracts and dorsal columns
What are the CNS gross abnormalities in Huntington disease?
Cell loss in basal ganglia, especially caudate nucleus + enlarged ventricles
Where are CNS tumors a) germinoma and b) Schwannoma most commonly located?
A) pineal gland
B) cerebellopontine angle (vestibular branch of CN VIII)
LEGAL: what is the a) Joiner standard and b) Khumo standard?
a) experts must limit their opinions to straight-forward extensions of the data and have limitations on what they say,
b) that all expert testimony must meet the Daubert standard
What is the difference between telangiectasia and cavernous angioma?
Telangiectasia: mult vascular channels with normal tissue (i.e. brain) in between;
Cavernous angioma: thin-walled vascular channels withOUT intervening tissue
What is Armanni-Ebstein lesion?
subnuclear vacuolization of renal tubules seen in hyperglycemia, hypothermia
What is the BMI equation?
BMI = mass / height^2
mass in kg, height in meters
What are the 3 metabolites diazepam gets metabolized to?
1) nordiazepam -> oxazepam (all other benzos have this one to)
2) temazepam -> oxazepam
What is laminar necrosis?
Separation of the cortical ribbon from underlying white matter, seen in ischemia, hypoxia, sometimes hypoglycemia
What does a) cerebral Aspergillosis look like grossly? b) cerebral Mucor?
Aspergillosis: Multifocal hemorrhagic abscesses (b/c hyphae of the fungus thrombose the vessel walls)
Mucor: hemorragic lesion/abescess in inferior frontal lobe (bc Mucor invades through cribriform plate)
Picks dementia - what does brain look like grossly and what is seen microscopically?
cerebral atrophy with preservation of the occipital lobes (frontotemporal dementia)
Pick bodies: rounded vague/matte cytoplasmic inclusions (as opposed to shiny ones of Parkinson’s)
ALS: what are the gross findings?
Atrophy of the anterior (motor, ventral) sensory roots as compared to dorsal
whiteness/demyelination of the lateral corticospinal (pyramidal) tracts
What drugs, when administered intrathecally, cause atrophy of the spinal cord and precipitated tubulin (pink crystal) histologically?
colchicine for spondylitis, vincristine for leukemia
What lesion do you see grossly in central pontine myelinolysis?
dark brown lesion in central mid-pons
What is Grinker myelinopathy and where is it seen?
multifocal perivenous hemorrhage and necrosis in brain and cerebellum;
with carbon monoxide intoxication
What is Alexander’s disease and what does it look like grossly & histologically?
GFAP-mutation disease of ASTROCYTES wherein they accumulate GFAP,
massive destruction of the white matter with preservation of overlying cortex & basal ganglia. ++ Rosenthal fibers
Where in the brain are arachnoid cysts most commonly seen?
Syvian fissure (lateral temporal lobe area)
What is hydranencephaly?
near absence of the cerebral hemispheres due to an intrauterine insult; brain is mostly a fluid-filled sac (“empty basket”)
What is seen histologically with rabies encephalitis?
Negri bodies (pink-purple intracytoplasmic inclusions), LACK of inflammation
What do each of the red, yellow, blue, and white boxes on the hazard diamond mean?
red: fire hazard (flash point temperature)
yellow: reactivity (denoate/chemical change/stability)
blue: health hazard
white: specific (acid, oxidizer, corrosive, radioactive, etc)
What do stress gastritis vs Curling ulcers look like grossly?
stress gastritis: red diffuse to streaky petechiae
Curling ulcers: ulcers in proximal duodenum with burns
What does the skull look like (and what is the terminology) in Crouzen, Saethre-Chotzen, Apert, Pfeffier, and Muenke syndromes?
craniosynostosis (premature fusion of the skull in an infant): scalloped ridges on the internal surface of the skull from compression of gyri, increased ICP
Black pigmentation of the colon(melanosis coli) is seen with what?
laxative abuse
Tetracycline antibiotics causes what histologically in the thyroid?
deposition of LIGHT BROWN pigment in follicles/ light brown colloid (it only looks black grossly)
Adipocere is caused by what bacterial species?
Clostridium
What will a) Foster slug vs b) Glaser slug look like on xray?
a) doughnut-like single fragment, OR multiple comma-shaped fragments
b) multiple pellets
Splenic gamna-gandy bodies are seen histologically in what conditions?
1 cause = portal HTN 2/2 cirrhosis
also in sickle cell anemia, hemochromatosis
What is the voltage cutoff for high vs low voltage electrocution?
1000 volts
How many layers of fibroblasts are present in a subdural hemorrhage at a) 5 days, b) 1 week, c) 2 weeks?
a) 5 cells thick on dural side
b) ~14 cells thick (2x the amount of days) on dural side
c) 1/2 dural thickness on dural side, PLUS earliest neomembrane on the arachnoid side
What is the smell and where are the following gases commonly encountered:
a) phosgene (COCl2),
b) phosphine (PH3)
A) odor of fresh hay/grass, with building fires with refrigeration units
B) order of garlic/decaying fish; with farms
What is pediculosis corporis?
Body lice
How many inches diameter is a a) 10 gauge, b) 16 gauge, and c) 28 gauge bore, and how would this be converted to centimetres if they show a metric ruler?
A) 0.775”
B) 0.662”
C) 0.550”
1 inch = 2.54 centimeters
What is Fahr’s disease?
Bilateral familial idiopathic basal ganglia calcification, with psych/neuro symptoms ie Parkinsonism
Which 0.22 projectile has a copper jacket?
0.22 Magnum
What is scromboid poisoning from?
Fish contaminated with high levels of histamines
What compound is vaping lung injury due to?
Vitamin E
What are the ranges for mild, moderate, and severe hypothermia?
A) mild: 32 to 35 C
B) mod: 28 to 32 C
C) severe: <28 C
What is Ludwig’s angina?
Bacterial infection / cellulitis of roof of mouth and neck, often from dental caries
What is grade 1, 2, and 3 diffuse axonal injury?
Grade 1: microscopic damage to axons without gross hemorrhage
Grade 2: micro damage to axons + corpus callosum hemorrhage
Grade 3: micro damage to axons + dorsal brainstem hemorrhage (/internal capsules, cerebellar peduncles)
What is the gross difference between primary traumatic brain stem hemorrhage and secondary (Duret) hemorrhage?
Primary: usually in posterior aspect of brain stem
Secondary: usually streaky and midline
What is seen microscopically with cerebral infarcts at:
1) 1-2 days after
2) ~5 days after
3) 1 week after
4) 1 month after
1) eosinophilic neuronal degeneration, early neutrophils
2) early macrophages and neovascularization
3) the above plus reactive astrocytes
4) decrease in cellular elements
What is the most common intracranial hemorrhage in neonates and what complication can it lead to?
Intraventricular hemorrhage, leading to hydrocephalus and polygyria(pseudopolymicrogyria: normal Histologically, unlike the malformation polymicrogyria)
How to distinguish Histologically between a pons infarction and central pontine myelinolysis?
Both will have loss of tissue (pale d/t demyelination) with macrophages, but CPM will have preservation of axons and neurons
What are the gross characteristics of the brain in Down syndrome?
Narrow superior temporal gurus, flattened occipital, shortened frontal lobes
What kind of force causes an oblique fracture of the bone? What is an abulsion fracture?
Torsion (just like spiral)
Avulsion: fracture in area where muscles/tendons attach (epi/metaphysis)
What metabolite of cocaine is physiologically active?
Norcocaine
What does the a) modified Griess test,
B) sodium rhodizonate test,
C) dithiooxamide test detect?
A) nitrite compounds produced by burning of smokeless powder to figure out range of fire
B) lead residue around entrance wound
C) copper residue around entrance
What mutation is associated with Lowe-Dietz syndrome and what COD does it predispose to?
TGF-beta mutation
Connective tissue disorder that predisposes to aortic dissection
What does the M-14, M-16, and AR15A2 have in common and what is difference?
All can have flash suppressors
M14: 5 slits
M16: 3 slits
AR15A2: 3 slits
How to differentiate the following birefringent crystals found in IVDA:
A) talc
B) potato and corn starch
B) microcrystalline cellulose
A) needle shaped, PAS NEGATIVE
B) Maltese cross, PAS positive
B) elongated rod, PAS positive
