Special Pathology Topics
Alcohol
Acetaldehyde produces the acute effects (CNS depression, acute gastitis, ulceration) and oral cancers Increased NADH/NAD+ ratio results in the more chronic effects like fatty changes in the liver and lactic acidosis
What gives the "Y" shaped mark
Laceration with abrasion, particularly on the skull
What is a compounding factor in the appearance of stab wound
Langer's lanes = pattern of elastic and collagenous fibers in the dermis
Case 2) Hyperactive 5 year old with distrubuted hearing and hypochromic anemia Family history reveals the boy lives with his sister, mother and maternal grandparents in an older area of your community On chart review, you see he was last seen for his preschool physical 1 yr ago, results of which were normal Hematocrit was low at 30%. Peripheral blood smear showed hypochromia and microcytosis. On physical exam today, you note the boy is in the tenth percentile for height and weight. His attention span is very short, making him appear restless, and he has difficulty following simple instructions. Except for language and social skills, he has reached most important developmental milestones
Lead Poisoning Hints: 1) Old house 2) Normal before the moving 3) Neurotoxic effects only on language, attention. 4) Anemia
What determins the length, depth, and width of the wound from a stab wound
Length of wound = width of the blad Depth of wound = length of blade Width of wound = thickness of blade
What radiation doses are associated with which pathologies?
Low dose (300 rad) = Depression of the bone marrow within 2 weeks os the exposure Medium Dose (1000rad) = Destruction of GI tract within days of exposure. Death can be result friom massive fluid loss High Dose (3000 rad) = fatal from CNS damage
What do enterance wounds looks like?
Marginal abrasions from the bullet hitting the skin Circular to oval wound
Cadmium Exposure
Mining, Battery Production Obstructive lung disease, lung cancer, renal tubular damage, skeletal abnormalities
What do exit wounds look like?
Non specific Often stallate, irregular, and lacerated
Cobalt Exposure
Occupational in the metal industry Acute respiratory distress, chronic interstital lung disease
fetal alcohol syndrome (FAS)
One of the leading preventable causes of intellectual disability in the US. Newborns of mothers who consumed alcohol during any stage of pregnancy have 🠕 incidence of congenital abnormalities, including pre- and postnatal developmental retardation, microcephaly, facial abnormalities (eg, smooth philtrum, thin vermillion border, small palpebral fissures), limb dislocation, heart defects. Heart-lung fistulas and holoprosencephaly in most severe form. One mechanism is due to impaired migration of neuronal and glial cells.
What are the types of wounding mechanisms used in gunshot injuries
Permanent Cavity (width of bullet): Direct physical interaction from the bullet. Bullet damages critical structures and the patient dies Delayed = the structures involved are not immediately lethal (leg) and the patient surivives Temporal Cavity Destruction is caused by the stretching and tearing the bullet produces. In a wake directly behind the projectile, the walls of the permanent cavity are temporarily stretched radially outward, then quickly contract back toward the permanent tract. A large temporary cavity is characteristic of high velocity rifle rounds (rifle > hanguns)
What is Pneumoconiosis
Pneumoconiosis is a interstital lung disease that results from inflammatory response that occurs when certain types of dust (1-5um) particles are inhaled. Asbestos is from the roof (was common in insulation), but affects the base (lower lobes). Silica and coal are from the base (earth), but affect the roof (upper lobes).
Diseases related to smoking
Pulmonary -Lung Cancer -Asthma Attack -COPD (Chronic Obstructive Pulmonary Disease) Cardiovascular -Heart Disease -Stroke Cancers: Bladder, Cervix, Esophagus, Kidney, Larynx, Lung, Oropharynx, Pancreas
How do you fill out a death certificatre
Remeber: Physicans can only sign a death certificate if it is a natural cause of death: You cannot sign if there accidents and any other injuries You fill out the Cause of death from most specific to broad in a logical squence (image) Any extra information that is not immediately related to the cause of death (risk factors, etc) go in the Part II (other significant coniditions) such as obesity, diabetes, etc
What is tissue bridging
"Bridging" of tissue from incomplete seperation of different soft tisusses (vessels, elastic fibers, nerves)
What is a Gray (Gy)? What is a Sievart (Sv)?
1 Gy = 100 rad. Measurment of radiation absorbed dose 1 Sv = 100 rem; measurement of Roentgen equivalent man, indication of radiation effect on biological tissue
What are the basic types of blunt force injruies
1) Abrasions = scratches/scapes and glazing/impact; when the force is applied tangentially and removes of the epidermis 2) Contusions = brusing/hematoma from breaking of blood vessles in thin, fatty skin 3) Lacerations = tearing of tissue from shearing or crushing force that creates contused margins. Common over bony prominences 4) Fractures of the skeletal system Note that these are not mutually exlcusive.
What are the mechanism of death of sharp force injury
1) Exsanguination (espically if multiple stabs) 2) Hemipericardium with cardiac tamponade 3) Asphayxia from inhalation of blood 4) Air embolism 5) Pneumothorax 6) Infection
What are some special fractures to be aware of
1. Bumper fractures (lateral tibitial platue) and Cervical Fractures in pedestrain involved with auto accidents 2. Child abuse fractures = rotation, spiral, or hinge exteremitiy and rib fractures 3. Hip fractrures in the eldery
What are the broad types of enviromental induced pathology
1. Enviromental: air pollution, metals, smoking 2. Occupational health risk: chemicals 3. Alcohol 4. Radiation
What is the most common deceleration injury
Transection of the Proximal Descending Thoracic Aorta at the aortic ischmus (proximal descending aorta just distal to origin of the left sublcavian artery) Xray will show a widened mediastinum
Pathological Findings of asbestosis
Asbestosis = Chronic, Progressive form of pulmonary fibrosis "Ivory white," calcified, supradiaphragmatic (A) and pleural (B) plaques are pathognomonic of asbestosis. Asbestos (ferruginous) bodies are golden-brown fusiform rods resembling dumbbells (C) found in alveolar sputum sample, visualized using Prussian blue stain, often obtained by bronchoalveolar lavage
Berylliosis
Associated with exposure to beryllium in aerospace and manufacturing industries. Granulomatous (noncaseating) on histology and therefore occasionally responsive to steroids. Increased risk of cancer and cor pulmonale
Silicosis
Associated with sandblasting, foundries, mines. Macrophages respond to silica and release fibrogenic factors, leading to fibrosis. It is thought that silica may disrupt phagolysosomes and impair macrophages, increasing susceptibility to TB. "Eggshell" calcification of hilar lymph nodes on CXR Increased risk of TB, cancer, cor pulmonale, and Caplan syndrome.
Nickel Exposure
Battery Manufacturing, Coins Contact Dermatitis, Cancers of the lung and nasal cavities
What is the pathogenesis of lead poisoning?
Binds to sulfhydryl groups in proteins Interferes with heme synthesis: Lead inhibits ferrochelatase and ALA dehydratase = less heme synthesis and increased RBC protoporphyrin. Also inhibits rRNA degradation -> RBCs retain aggregates of rRNA (basophilic stippling). Also Interferes with calcium metabolism, Zn dependent enzymes, synthesis of steroids and cell membranes
Compare blunt force to sharp force
Blunt force is more likely to have lacerations because it tears the skins Sharp forces
Case 5) A 20-year-old white female arrived by ambulance at the hospital approximately 60 min after being found unconscious at her mobile home. She had been intubated by the Emergency Medical Services and had received 100% supplemental oxygen en route to the hospital. The patient's 21-year-old husband was also found at the scene and brought to the hospital. Although initially disoriented, restless, and combative, he was lucid at the time of arrival in the emergency department. From his history, it was determined that the couple's usual heater was in disrepair, and a portable propane heater was the sole source of heat in their unventilated mobile home. During the initial physical examination, the patient was noted to be combative and confused. Her blood pressure was palpable by cuff measurement at 80 torr systolic. She was being ventilated by a volume-cycled ventilator which she triggered 26 times a minute. Carbonaceous material was found in the nares, oropharynx, and adherent to the endotracheal tube. No burns of the skin, nasal hair, face, or eyebrows were present. Peripheral cyanosis was noted in her nail beds. The measured carboxyhemoglobin concentration at the time of admission was 7%. A plasma and urine toxicology screen was negative. The initial chest radiograph was interpreted as showing bilateral alveolar infiltrates consistent with the adult respiratory distress syndrome.
Carbon Monoxide
Whjat is cause, manner, and mechanims of death
Cause of death = disease/injury that produces a physiological disruption of the body which results in death [MI, cancer, gunshot wound] Mechanism of death = the actual physiological disruption of the body that resulted in death [Exsanguination] Manner of death: how the death came about. 1) Natural 2) Accident 3) Suicide 4) Homicide 5) Undetermined 6) Pending
Ionizing Radiation Pathology
Cell death, Carcinogenesis, Tetratogensis Determinants of injury 1) Rate of delivery: divided dose let cell heals in interval peroid 2) Field size: higher doses can be tolerated in smaller fields 3) Cell proliferation: Rapidly dividing cells are more vulnerable like gonads, bone marrows, lymphoid tissues, mucosa of the GIT 4) O2 status = poorly vascularized tisses are less sensitive 5) Vascular damage = impaired healing
What are some occupational health risks?
Choloform (CCL4) = liver and kidney toxicity Benzene (alkylating agents) = acute leukemia Mineral dust (silica, coal, absestos) pneumoconosis and mesothelioma Vinyl cholide (PVC pipes thus plumbers) = liver angiosacroma
What are enviromental diseases?
Conditions caused by exposure to chemicals or physical agents in the ambient, workplace, and personal enviromental
What are some of the internal blunt injuries and when are seem?
Contusions and Lacerations of internal organs; often seen in MVA. Note that outside damage does not equal inside damage Front impact/Windshield = head, chest (heart, lungs, liver, spleen injuries, lacerations, contusions), and fractures of rubs, sternum and knee
How do you diagnosis and treat lead poisoning?
Dx: Blood lead levels, increase in free erythrocyte protoporphyrin Rx: Chelating agents: 1) Succimer used for chelation for kids (It "sucks" to be a kid who eats lead). 2) Wrist and foot drop -> Dimercaprol and EDTA are 1st line of treatment
Asbestos
Exposure: Old roofing material, shipyard workers Associated with Latent (long time from first abestos exposure to symptoms): Lung Cancer (Bronchogenic carcinom) and Mesothelioma (lining of internal organs) Synergetic effect with cigarette smoke on the development on lung cancer (Cigarette smoke does not cause mesothelioma)
Review: What are the carcinogenes found in tobacco smoke
Formaldehyde Lead Arsenic Benzene Nitrosamine Polycyclic aromatic hydrocarbons (PAH)
Lead Exposure in Children
From ingestion of paint dust/flakes; contaminated air, food water Unique findings Encapthopathy (hyperactivity, headaches, irritability), lead lines in epiphysis Heme (same as adults): Microcytic hypochromatic anemia, punctuate basophilic stippling of RBC, Fanconi syndrome, lead colic (abdominal cramping)
What are track like bruises?
Give a clue about what object was used
Arsenic Toxicity
Herbicides (vineyard workers), metal smelting Arsenic inhibits lipoic acid. Arsenic poisoning clinical findings: imagine a vampire (pigmentary skin changes, skin cancer), vomiting and having diarrhea, running away from a cutie (QT prolongation) with garlic breath. Acute: CNS toxicity Chronic: 1. Cancers of the skin (SSC), Lung Cancer, and Angiosacroma of the Liver ; GI, cardiovascular, hematological dysfunction Arsenic Rx: Dimercaprol, succimer
What is Sideroblastic Anemia?
Hypochromic microocytic anemia → small size, lack of color Lab findings: 🠕 iron, normal/↓TIBC, 🠕 ferritin. Ringed sideroblasts (with iron-laden, Prussian blue-stained mitochondria) seen in bone marrow. Peripheral blood smear: basophilic stippling of RBCs Treatment: pyridoxine (B6 , cofactor for ALA synthase).
Chromium Exposure
Industrial exposure Lung cancer
Gunshot Wounds
Injury can vary greatly depending on 1) Weapon itself = velocity and caliber 2) Ammunication = each have different wounding mechanisms 3) Range of fire = the gunpowder itself can damage if close enough 4) Anatomy involved
Mercury Toxicity
Inorganic: work related with proximal tubular necrosis Organic (methyl mercury): contaminated fish (Highest in swordfish, shark, tilefish, king mackerel). In utero, can lead to deafness, blindness, cerebral pasly, mental retardation. Mercury Rx: Dimercaprol,succimer
Case 3) You are on duty in the ER in a small community. A truck carrying radioactive material went 200 feet down an embankment. It came to rest about 15 feet from a river bank, and is on fire. The driver and his assistant have burns and other minor injuries. A highway patrol officer was 1st on the scene and contacted a health physicist. They found that the driver and assistant are externally contaminated with radioactive material, emitting beta and gamma radiation.
Ionizing Radiation Acute Radiation Sickness
Case 4) 42 -year -old woman presents after six months of therapy for breast cancer with contracture of the left arm. The patient had microcalcifications noted by mammography eight months previously. A needle biopsy showed invasive ductal carcinoma. An excisional biopsy (lumpectomy) was performed, which showed a 1 -cm focus of carcinoma. The margins were negative for tumor. Pathologic examination of axillary lymph nodes at the time of the lumpectomy showed no evidence for metastatic tumor. She received chemotherapy and radiation therapy. In the last few weeks there has been marked thickening of the skin over the left axillary region. A skin biopsy is performed
Ionzing Radiation Radiodermatitis
Where what are the types of abrasions and when are you likely to see abrasions
Scratches = Superficial Graze/sliding/brush absrasions = deeper (MVA) Impact abrasions = force perpendicular to skin aginst a bony prominence (knees on MVA) Some situations: Strangulations (from fingernails) Hangings (rope/ligature abrasions) MVA (seltbelt abrasions)
Case 1) A 62-year-old man presents with cough and hemoptysis. He also noted a 10-pound weight loss in the last two months. Past medical history is notable for a 20-year history of hypertension. He had an anterior myocardial infarct five years ago. The patient is sedentary and has low exercise tolerance. He had worked in a shipyard for 20 years. A chest x-ray and pulmonary function tests one year ago were consistent with emphysema. The patient smoked 3 packs of cigarettes a day for 30 years. A chest x-ray shows a 10-cm mass in the right hilar region. A bronchoscopy is performed and a transbronchial biopsy obtained.
Smoking + Absestos Smoking: Hypertension, Anterior Myocardial Infaract, Emphysema, Lung Cancer Absestos: Lung cancer, shipyard
Mnenomic for the Symptoms of Lead Poiosning
Symptoms of LEAD poisoning: Lead Lines on gingivae (Burton lines) and on metaphyses of long bones on x-ray. Encephalopathy and Erythrocyte basophilic stippling. Abdominal colic and sideroblastic Anemia. Drops—wrist and foot drop.
What kinds of deaths need to be reported to the ME officer?
The coroner (elected, not a doctor) or medical examiner need to be informed if the manner of the death is anything outside of natural Accidents, Suicide, Homocidies, unknown, drugs, etc all need to be reported Physicans can only sign a death certificates if there was a natural cause of death
Explain why the range of the gunshot wound is important
The gunpowder can be damaging too and produce special injuries if close enough 1) Contact = soot deposition and searing from the burned gunpowder + muzzle imprint 2) Intermediate Range (2 in-2 ft): Sippling abrasions from the unburnt pwoder where diameter = distance and they develop antemortem 3) Distant (>2 feet): no injury from gunpowder
What is forensic pathology
The investigation and certification of cause and manner of death Using: scene investigation, autopsy, review of medical history, toxicology Parallel, indepedent, and objective from the other investigations
Lead Exposure in Adults
Usually from occupational exposure (battery manufacturing) Unique to adults: Memory Loss, perpherial neuropathy (from demylination) of flexors: wrist/foot drop Heme: Microcytic hypochromatic anemia, punctuate basophilic stippling of RBC, Fanconi syndrome, lead colic (abdominal pain)
What are the sharp force injuries
Wounds caused by pointed and sharp edged weapons. Note that force is hard to compare and minial force is needed after peneterating the skin 1) Stab wounds = depth of the wound > length on the skin. Can determine the type of weapon used 2) Incised wounds (cuts) = depth of the wound < skin wound length. Caused by a drawing along the skin (wrinkle wound). Cannot detemrine what weapon was used Chop wounds = made by heavy instruments with a cutting edge (axes, machetes); often has grooves/fractures in the underlying bone Therapeutic/diagnositic wounds
Carbon Monoxide
a colorless, odorless, and poisonous gas 250x more affinity fotr Hb than O2 thus making carboxyHb → left shift → inhibits O2 release → less unloading → tissue hypoxia Sx: Headache, dizziness. Cherry red coloration of skin and mucus membranes Rx: 100% O2, hyperbaric O2
Helpful link to understanding permanent vs. temporary cavity
http://theprepperpages.com/what-preppers-need-to-know-about-gunshot-wounds-in-3-minutes/
