Friday, May 24, 2013

Difference between Esophageal varices and Mallory-Weiss syndrome



  • Laceration at the GE junction due to severe prolonged vomiting (MW syndrome)



  • Dilated submucosal veins in the lower third of the esophagus ,usually secondary to portal hypertension (EV)



  • Most Common Cause : alcoholism in (MW syndrome) , Cirrhosis in (EV)



  • Presentation : Mild hematemesis in (MW syndrome) , Massive hematemesis when ruptured in (EV) 



  • Complication : Boerhaave syndrome (esophageal rupture) in (MW syndrome) , Potentially fatal hemorrhage in (EV) 
both can possibly lead to death in alcoholics.

Monday, May 20, 2013

Colon polyps types description and their progression to malignancy



  • Type : Hyperplastic polyp 


Description
Sawtooth glandular epithelium with proliferation of globet and columnar epithelial cells

Progression to Malignancy
No
  • Type: Tubular adenoma


Description
Pedunculated

Progression to Malignancy
Low (4%)




  • Type : Tubulovillous adenoma


Description
Combines both

Progression to Malignancy
Intermediated



  • Type : Villous adenoma


Description
Sessile

Progression to Malignancy
High (30%)


  • Type : Famililal Adenomatous Polyposis


Description
Autosomal Dominant Thousands of Colonic adenomatous polyps

Progression to Malignancy
100% (by 40 year)




  • Type : Gardner syndrome


Description
Autosomal Dominant Associated with desmoid tumors

Progression to Malignancy
~ 100%




  • Type : Turcot Syndrome


Description
Associated with CNS tumors(gliomas)

Progression to Malignancy
Highly


  • Type : Peutz-Jeghers Syndrome


Description
Autosomal Dominant Hamartomas. Melanin Pigmentation of the buccal mucosa

Progression to Malignancy
No



Figure : Colonic adenocarcinoma of cecum


  • Colon Cancer 


HNPCC (lynch Syndrome)

  • Autosomal Dominant
  • Mutation of DNA nucleotide mismatch repair gene
  • Increased risk of endometrial and ovarian carcinoma



Case studies electrolyte and acid-base disorder

Case 1

Mr. Frank is a 60 year-old with pneumonia. He is admitted with dyspnea, fever, and chills. His blood gas is below:
pH 7.28
CO2 56
PO2 70
HCO3 25
SaO2 89%
What is your interpretation?
  • Uncompensated respiratory acidosis

Case 2

Ms. Strauss is a 24 year-old college student. She has a history of Crohn's disease and is complaining of a four day history of bloody-watery diarrhea. A blood gas is obtained to assess her acid/base balance:
pH 7.28
CO2 43
pO2 88
HCO3 20
SaO2 96%
What is your interpretation?
  • Uncompensated metabolic alkalosis

Case 3

Mr. Karl is a 80 year-old nursing home resident admitted with urosepsis. Over the last two hours he has developed shortness of breath and is becoming confused. His ABG shows the following results:
pH 7.02
CO2 55
pO2 77
HCO3 14
SaO2 89%
What is your interpretation?
  • Combined respiratory and metabolic acidosis

Case 4

Mrs. Lauder is a thin, elderly-looking 61 year-old COPD patient. She has an ABG done as part of her routine care in the pulmonary clinic. The results are as follows:
pH 7.37
CO2 63
pO2 58
HCO3 35
SaO2 89%
What is your interpretation?
  • Fully compensated respiratory acidosis

Case 5

Ms. Steele is a 17 year-old with intractable vomiting. She has some electrolyte abnormalities, so a blood gas is obtained to assess her acid/base balance.
pH 7.50
CO2 36
pO2 92
HCO3 27
SaO2 97%
What is your interpretation?
  • Hypochloremic metabolic alkalosis (anion gap)

Case 6

Mr. Longo is a 18 year-old comatose, quadriplegic patient who has the following ABG done as part of a medical workup:
pH 7.48
CO2 22
pO2 96
HCO3 16
SaO2 98%
What is your interpretation?
  • Respiratory alkalosis with metabolic acidosis

Case 7

Mr. Casper is a 55 year-old with GERD. He takes about 15 TUMS antacid tablets a day. An ABG is obtained to assess his acid/base balance:
pH 7.46
CO2 42
pO2 86
HCO3 29
SaO2 97%
What is your interpretation?
  • Uncompensated Metabolic alkalosis 

Case 8

Mrs. Dobins is found pulseless and not breathing this morning. After a couple minutes of CPR she responds with a pulse and starts breathing on her own. A blood gas is obtained:
pH 6.89
CO2 70
pO2 42
HCO3 13
SaO2 50%
What is your interpretation?
  • Combined respiratory acidosis with metabolic acidosis

Case 9

After resuscitating Mrs. Dobins, you find Mr. Simmons to be in respiratory distress. He has a history of Type-I diabetes mellitus and is now febrile. His ABG shows:
pH 7.00
CO2 59
pO2 86
HCO3 14
SaO2 91%
What is your interpretation?
  • Combined respiratory acidosis with metabolic acidosis

Case 10

Ms. Berth was admitted for a drug overdose. She is being mechanically ventilated and a blood gas is obtained to assess her for weaning. The results are as follows:
pH 7.54
CO2 19
pO2 100
HCO3 16
SaO2 98%
What is your interpretation?
  • Respiratory alkalosis with metabolic acidosis

Case 11

Mrs. Puffer is a 35-year-old single mother, just getting off the night shift. She reports to the ED in the early morning with shortness of breath. She has cyanosis of the lips. She has had a productive cough for 2 weeks. Her temperature is 102.2, blood pressure 110/76, heart rate 108, respirations 32, rapid and shallow. Breath sounds are diminished in both bases, with coarse rhonchi in the upper lobes. Chest X-ray indicates bilateral pneumonia.
ABG results are:
pH= 7.44
PaCO2= 28
HCO3= 24
PaO2= 54

  • Compensated respiratory alkalosis

Case 12

Mr. Worried is a 52-year-old widower. He is retired and living alone. He enters the ED complaining of shortness of breath and tingling in fingers. His breathing is shallow and rapid. He denies diabetes; blood sugar is normal. There are no EKG changes. He has no significant respiratory or cardiac history. He takes several antianxiety medications. He says he has had anxiety attacks before. While being worked up for chest pain an ABG is done:
ABG results are:
pH= 7.48
PaCO2= 28
HCO3= 22
PaO2= 85

  • Uncompensated respiratory alkalosis

Case 13

Mr. Sweet, a 24-year-old DKA (diabetic ketoacidosis) patient from the ED. The medical diagnosis tells you to expect acidosis. In report you learn that his blood glucose on arrival was 780. He has been started on an insulin drip and has received one amp of bicarb. You will be doing finger stick blood sugars every hour.
ABG results are:
pH= 7.33
PaCO2= 25
HCO3=12
PaO2= 89
  • Metabolic acidosis with respiratory alkalosis

Case 14

A 24 year-old woman is found down in Pioneer Square by some bystanders. The medics are called and, upon arrival, find her with an oxygen saturation of 88% on room air and pinpoint pupils on exam. She is brought into the Harborview ER where a room air arterial blood gas is performed and reveals: pH 7.25, PCO2 60, PO2 65, HCO3 -  26. On his chemistry panel, her sodium is 137, chloride 100, bicarbonate 26.

  • Acute Uncompensated respiratory acidosis 

Case 15

A 60 year-old man with amyotrophic lateral sclerosis is brought into clinic by his family who are concerned that he is more somnolent than normal. On further history, they report that he has been having problems with morning headaches and does not feel very refreshed when he wakes up. An arterial blood gas is performed and reveals:  pH 7.37, PCO2 57, PO2 70, HCO3- 32.

  •  Chronic Compensated respiratory acidosis

Case 16

A 65 year-old man is brought into the VA hospital with complaints of severe nausea and weakness. He has had problems with peptic ulcer disease in the past and has been having similar pain for the past two weeks. Rather than see a physician about this, he opted to deal with the problem on his own and, over the past week, has been drinking significant quantities of milk and consuming large quantities of TUMS (calcium carbonate).  On his initial laboratory studies, he is found to have a calcium level of 11.5 mg/dL, a creatinine of 1.4 and bicarbonate of 35. The resident working in the ER decides to draw a room air blood gas that reveals: pH 7.45, PCO2 49, PO2 68, HCO3- 34. On his chemistry panel, the sodium is 139, chloride 95, HCO3- 34.
  • Compensated metabolic alkalosis

Case 17

A 45 year-old woman with a history of inhalant abuse presents to the emergency room complaining of dyspnea. She has an SpO2 of 99% on room air and is obviously tachypneic on exam with what appears to be Kussmaul’s respirations. A room air arterial blood gas is performed and reveals: pH 6.95, PCO2 9, PO2 128, HCO3- 2. A chemistry panel revealed sodium of 130, chloride 98, HCO3- 2.

  • Increased Anion gap metabolic acidosis with respiratory alkalosis

Case 18

A 68 year-old man with a history of very severe COPD (FEV1 ~ 1.0L,  < 25% predicted) and chronic carbon dioxide retention (Baseline PCO2 58) presents to the emergency room complaining of worsening dyspnea and an increase in the frequency and purulence of his sputum production over the past 2 days. His oxygen saturation is 78% on room air. Before he is place on supplemental oxygen, a room air arterial blood gas is drawn and reveals: pH 7.25, PCO2 68, PO2 48, HCO3-  31.

  • Respiratory acidosis with metabolic compensation

Case 19

A 47 year-old man with a history of heavy alcohol use presents with a two-day history of severe abdominal pain, nausea and vomiting. On exam, his blood pressure is 90/50 and he is markedly tender in his epigastrum. His initial laboratory studies reveal sodium of 132, chloride 92, HCO3- 16, creatinine 1.5, amylase 400 and lipase 250. A room air arterial blood gas is drawn and reveals pH 7.28, PCO2 34, PO2 88, HCO3- 16.


  • Increased anion gap metabolic acidosis with respiratory compensation

Case 20

A climber is coming down from the summit of Mt. Everest. At an altitude of 8,400 m (PB ~ 272 mmHg), he has a blood gas drawn while breathing ambient air as part of a research project. The blood gas reveals pH 7.55, PCO2 12, PO2 30 and HCO3- 10.5.


  • Respiratory alkalosis with metabolic compensation

Case 21

A 57 year-old woman presents with 2 days of fevers, dyspnea and a cough productive of rust-colored sputum. Her room air oxygen saturation in the emergency room is found to be 85% and the intern decides to obtain a room air arterial blood gas while they are waiting for the chest x-ray to be done. The blood gas reveals: pH 7.54, PCO2 25, PO2 65, HCO3- 22


  • Acute uncompensated respiratory alkalosis

Genetic conditions (Germline genetic disease) Involved chromosomal sites



  • 5q21 is the location of the APC mutation that predisposes for FAP.



  • 11p13 is the site of the WT-1 tumor gene



  • 13q14 is the site of the RB retinoblastoma gene.



  • 17q11 is the site of the NF-1 neurofibromatosis gene,



  • 22q12 is the site of the NF-2 neurofibromatosis gene.

Thursday, May 16, 2013

CT SCAN OF HEAD

          

                 

1.Interhemispheric fissure - Centered on the midline
2.Cortical  sulcation  Of cerebrum and cerebellum
3.Cerebral cortex  width, Density (no calcifications or hemorrhages), No separation from the calvarium, No abnormal fluid collection (convex or concave) between the cerebral cortex and calvarium
4.Ventricles – Shape, Size, Symmetry (no unilateral or circumscribed enlargement), No signs of increased intracranial pressure (e.g. effaced sulci, narrowing or unilateral expansion of ventricles)
5.White matter Density (homogeneous, especially at periventricular sites)- No hypodensities (circumscribed, lacunar, or diffuse), No hyperdense changes (calcification, hemorrhage), Normal width in relation to cortex
6. Basal ganglia- Position, internal and external capsule,  Delineation

7. Thalamus – Density
8. Brain stem – Shape, Density (homogeneous), No focal abnormalities
9. Cerebellum- General form (symmetry), Cortex (width, sulcation), White matter (homogeneous density)
10. Intracranial vessels- No abnormal dilatation, No vascular malformations








  • Contusions occur at the inferior and polar surfaces of the frontal and temporal lobes secondary to contact with bony surfaces during deceleration or due to depressed skull fractures. 
  • Produced by damage to parenchymal blood vessels leading to petechial haemorrhage and oedema.

  • Contusions develop in surface grey matter tapering into white matter.
  • Contusions are seen as multiple focal areas of low or mixed attenuation intermixed with tiny areas of increased density representing petechial haemorrhage.




  • The CT appearance of fresh blood (acute hemorrhage) is that of a white (hyperdense) area in comparison to the grey colored brain. 
  • After a week, blood starts to appear grey like the brain or slightly darker than the brain. At this point, it is called a subacute hemorrhage (isodense or slightly hypodense).
  • After several weeks, blood appears much darker than the grey brain, and it is then called a chronic hemorrhage (hypodense). 
  • Bleeding may occur in four areas within the skull, as intraparenchymal, subarachnoid, subdural or epidural hemorrhages











              




INTRAVENTRICULAR HEMORRHAGE 


RING ENHANCING LESION SUGGESTIVE OF BRAIN ABSCESS( IN THIS CASE ), METASTASIS AND GLIOMA


    SUMMARY
    • Symmetry—Compare left and right sides of the cranium


    • Midline—Look for midline shift
    • Cross-sectional anatomy—Review anatomical landmarks for each slice
    • Brain tissue—Gray matter, white matter, intracerebral lesions
    • CSF spaces—Ventricles, basal cisterns, cortical sulci, and fissures
    • Skull and soft tissues—Scalp swelling, fractures, sinuses, orbits
    • Subdural windows—Look for blood collections adjacent to the skull
    • Bone windows—Skull, orbits and sinuses, intracranial air
    • Targeted Approach to CT Interpretation
    • Trauma—Blood (extra-axial, intraparenchymal), cerebral edema, fractures, pneumocephalus, scalp swelling, coup, and contra-coup injuries


    • Headache—Blood in the basilar cisterns (SAH), masses, hydrocephalus, cerebral venous sinuses thrombosis, paranasal sinusitis
    • Stroke—Examine region of neurological deficit for blood, edema.

    Wednesday, May 15, 2013

    Neoplasia : Differentiation and anaplasia

    Differentiation and anaplasia:
    Apply to the parenchymal cells of neoplasms

    Differentiation



    Extent to which parenchymal cells resemble comparable normal cells, both morphologically and functionally
    Well-differentiated tumors- cells resemble the mature normal cells of tissue of origin; better retains the fx of normal cells
    Evolves from maturation or specialization of undifferentiated cells as they proliferate
    Poorly-differentiated tumors – primitive-appearing, unspecialized cells
    Does retain fx of normal cell; may acquire other fx’s such as elaboration of fetal ptns or ectopic hormone production
    Derives from proliferation w/out maturation
    Benign tumors usually well-differentiated
    Malignant tumors usually range from anaplastic to well-differentiated

    Anaplasia

    Lack of differentiation
    Example of anaplastic tumors = malignant neoplasms composed of undifferentiated cells
    More rapidly growing and the more anaplastic a tumor, the less likely it is that there will be specialized functional activity

    Morphology of Anaplasia:

    Pleomorphism – variation in size and shape of both cell and nuclei
    Hyperchromatic nuclei; nuclei contain an overabundance of DNA
    Nuclei are too large for the cell
    Nuclear to cytoplasmic ratio may reach 1:1 instead of normal 1:4 or 1:6
    Chromatin is often coarsely clumped and distributed along the nuclear mbr
    Usually see large nucleoli
    High proliferative activity
    Large numbers of mitoses
    Atypical, bizarre mitotic figures sometimes w/ tripolar, quadripolar, or multipolar spindles
    Tumor giant cells
    Some possess only a single huge polymorphic nucleus, others w/ two or more nuclei
    Loss of normal polarity; grow in sheets or large masses tumors in an anarchic, disorganized fashion
    Vascular stroma is often scant; large central areas may undergo necrosis


    Variations in cell growth and differentiation: normal and abnormal.

    Increased growth.

    Increased growth occurs in a tissue or organ due to increased functional demand. It can be the result of hyperplasia, hypertrophy or a combination of both. Stimuli for increased growth include hormones, growth factors and work against resistance.
    Hyperplasia is an increase in cell number by cell division, often leading to an increase in the size of an organ.
    Hypertrophy is an increase in cell size without cell division, usually leading to an increase in the size of an organ.
    Both hyperplasia and hypertrophy can be physiological or pathological.

    Some examples of physiological hyperplasia

    The breast undergoes hyperplasia during puberty, pregnancy, and lactation, stimulated by hormones such as oestrogens, progesterone and prolactin.
    Red cell precursors in the bone marrow undergo hyperplasia at high altitude, stimulated by erythropoietin, which has been evoked by hypoxia.
    The thyroid undergoes hyperplasia in puberty and pregnancy, stimulated by increased metabolic demand.

    Some examples of physiological hypertrophy

    Skeletal muscle undergoes hypertrophy stimulated by increased muscle activity on exercise.
    Cardiac muscle undergoes hypertrophy stimulated by sustained outflow increase in athletes.
    Myometrium undergoes hypertrophy in pregnancy stimulated by oestrogens

    Some examples of pathological hyperplasia

    The prostate gland undergoes hyperplasia, stimulated by oestrogen.
    The adrenal cortex undergoes hyperplasia (Cushing’s syndrome) stimulated by ACTH produced by pituitary, lung or other tumours.
    The thyroid gland undergoes hyperplasia in Graves’ disease, stimulated by Thyroid-stimulating autoantibody.
    The parathyroid gland undergoes hyperplasia stimulated by hypercalcaemia.
    The endometrium undergoes hyperplasia stimulated by oestrogen.
    Myointimal cells undergo hyperplasia in atheromatous plaques stimulated by Platelet Derived Growth Factor.
    Keratinocytes in skin undergo hyperplasia in psoriasis, stimulated by cytokines released in an immune response.

    Some examples of pathological hypertrophy

    Cardiac muscle of the left ventricle undergoes hypertrophy because of increased outflow pressure eg systemic hypertension, aortic valve disease
    Cardiac muscle of the right ventricle undergoes hypertrophy because of increased outflow pressure eg pulmonary hypertension, pulmonary valve disease.
    Arterial smooth muscle undergoes hypertrophy in hypertension.
    Decreased size of tissue or organ
    This can occur in a tissue or organ due to developmental failure, or to reduction in size of a previously normal organ. This is atrophy.
    Atrophy is a decrease in cell size and/or number in a previously normal tissue or organ. Decrease in cell number is mediated by apoptosis; decrease in cell size by a reduction in cell growth. Atrophy can be physiological or pathological.

    Some examples of physiological atrophy

    In the embryo & fetus, the notochord and branchial clefts undergo atrophy.
    In the neonate, the umbilical vessels and ductus arteriosus undergo atrophy.
    In early adulthood, the thymus undergoes atrophy.
    In old age the uterus, testes, brain and bone all atrophy.

    Some examples of pathological atrophy

    Loss of function causes muscle atrophy and osteoporosis in immobilisation or weightlessness.
    Loss of innervation causes muscle atrophy in nerve transection or poliomyelitis.
    Loss of blood supply causes skin atrophy or bedsores in peripheral vascular disease or excess pressure.
    Severe malnutrition causes atrophy in many tissues.
    Loss of hormonal stimulation causes atrophy of adrenal cortex, thyroid, and gonads in hypopituitarism.
    Excess hormones can cause atrophy: excess corticosteroids cause skin atrophy.

    Abnormal differentiation
    When mature tissues grow and differentiate abnormally, they can undergo metaplasia, dysplasia or both.

    Metaplasia

    Is defined as the transformation of one fully differentiated cell type into another.
    Is an adaptive response to environmental stress, usually chronic irritation or inflammation; metaplastic tissues are better able to withstand the adverse environmental changes than are normal tissues
    Is caused by activation and/or repression of groups of genes involved in the maintenance of cellular differentiation
    There is no intrinsic gene defect (as there is in neoplasia), therefore metaplasia is reversible.
    But, metaplastic tissues are more genetically unstable than their normal counterparts, so they may undergo further transformation to dysplasia and neoplasia
    Can affect epithelial or connective tissue cells

    Epithelial metaplasia can be:

    Squamous: other epithelia transform to squamous epithelium.
    Glandular: other epithelia transform to glandular epithelium.

    Some examples of Squamous metaplasia are:

    Ciliated pseudostratified columnar epithelium of respiratory tract; due to smoking, bronchiectasis, or chronic bronchitis.
    Simple columnar epithelium of endocervix; due to changes of pH, injury, inflammation.
    Transitional cell epithelium of bladder; due to Schistosomal infection or bladder calculi.

    Some examples of Glandular metaplasia are:

    Stratified squamous epithelium of oesophagus transforms to simple columnar epithelium due to gastro-oesophageal reflux: Barrett’s oesophagus.
    Simple columnar epithelium of stomach transforms to intestinal epithelium, in chronic gastritis due to Helicobacter pylori

    Mesenchymal metaplasia is much less common than epithelial metaplasia. There are three main types:

    Osseous metaplasia – in old scars such as tuberculous scars in the lungs, in atheromatous plaques and in chronically damaged muscle
    Chondroid metaplasia – in similar conditions to osseous metaplasia
    Myeloid metaplasia (also known as extramedullary haemopoiesis) – in the spleen, liver and lymph nodes in patients with myeloproliferative diseases

    Dysplasia refers to cells of abnormal phenotype that are not yet neoplastic, but are predisposed to be.

    Encountered primarily in the epitheli
    It is a premalignant process.
    It is often preceded by metaplasia.
    It is usually irreversible.
    There is disordered maturation: the phenotype of the abnormal cells approaches that of malignant cells. Loss in uniformity of the individual cells as well as a loss in their architectural orientation. It is characterised by increased cell division, atypical cell morphology and lack of differentiation.
    Considerable architectural anarchy
    Considerable pleomorphism
    Hyperchromatic nuclei
    Nuclei are too large for cell
    Increase numbers of mitotic figures, but conform to normal patterns; may appear in abnormal location w/in the epithelium

    Examples include:

    in str sq epithelium, mitoses are not confined to basal layers, may occur in surface cells.
    Colonic epithelial dysplasia in longstanding ulcerative colitis.
    Cervical Intraepithelial Neoplasia (CIN).
    Glandular dysplasia in Barrett’s oesophagus
    Paget’s disease of bone.

    Carcinoma in situ

    When dysplastic changes are marked and involve the entire thickness of the epithelium
    Epithelial dysplasia almost invariably comes before the appearance of cancer
    Dysplasia does not necessarily progress to cancer.

    Tuesday, May 14, 2013

    What is your Clinical Diagnosis of these images ?

    Clinical Diagnosis ???






    Clinical Diagnosis ???








    Note* : Please give your Answer in the comment's option 

    Thursday, May 2, 2013

    Examples of non-random chromosomal abnormalities in neoplastic diseases

    Exchange of genetic material  between  two  genes, leading to the development of novel fusion gene which acts as an oncogene.

    Epidemiology of Cancer

    Epidemiology of Cancer:
    • Over last 50 yrs, the overall cancer death rate has significantly incr for men; for women, it has fallen slightly
    • Increase in men is due to lung cancer
    • Improvement for women is due to decline in death rates from cancers of uterus, stomach, liver, and carcinoma of the cervix
    • Carcinoma of the lung has incr in both sexes; beginning to decline in men, but still incr in women
    • Carcinomas of breast are 2.5X more frequent than carcinomas of lung, but lung cancer is leading cause of cancer deaths in women
    • Decrease in death from stomach and liver carcinomas – perhaps due to decr in dietary carcinogens
    Cancer incidence and cancer death for men:
    Cancer incidence and cancer deaths for women:
    Geographic and Environmental Factors:
    • Much of geographic differences are consequences of environmental influences
    • Rates of cancer for immigrants comes closer to US rates of cancer with each succeeding generation
    Environmental Factors:
    1. UV rays
    2. Asbestos, vinyl chloride, 2-naphthylamine 
    • Persons more than 25% overweight have a higher death rate from cancer
    • Alcohol – incr risk for carcinomas of oropharynx, larynx, esophagus, and liver
    • Smoking – incr risk for cancer of mouth, pharynx, larynx, esophagus, pancreas, bladder, and lung dz
    • Smoking is single most important environmental factor contributing to premature death in the US
    • Alcohol and tobacco together – incr risk of cancers in upper aerodigestive tract
    • Risk of cervical cancer is linked to age at first intercourse and the number of sex partners
    Age:
    • Each age group has its own predilection to certain forms of cancer
    • Striking incr in mortality from cancer in 55-74 y/o
    • Under 15 y/o:
    • Cancer accounts for about 10% of deaths in this group
    • Most common is acute leukemia and neoplasms of the CNS
    Heredity:
    • For a large number of cancers, there are environmental influences and hereditary predisposition’s
    Inherited Cancer Syndromes – inheritance of a single mutant gene greatly incr risk of developing a tumor
    • Tumors involve specific sites and tissues
    • Tumors w/in this group are often associated w/ a specific marker phenotype
    • Both incomplete penetrance and variable expressitivity are noted
    Familial Cancers
    • Almost all sporadic cancers have been reported to occur in familial forms
    • Early age at onset, tumors arising in two or more close relative of index case, and sometimes multiple or bilateral tumors
    • Not associated w/ specific marker phenotypes

    Autosomal Recessive Syndromes of Defective DNA Repair:
    • Example is xeroderma pigmentosa

    Autosomal Dominant Neoplasia Syndromes
    RB, retinoblastoma; FAP, familial adenomatous polyposis; APC, adenomatous polyposis coli; MEN, multiple endocrine neoplasia; RET, rearranged during  transfection; VHL, von Hippel-Lindau.

    Defective DNA Repair Syndromes

    • ATM, ataxia-telangiectasia mutated.
    • *Ataxia-telangiectasia is also associated with cerebellar ataxia.




    Acquired Preneoplastic Disorders:
    • A premalignant lesion is an identifiable local abnormality associated with an increased risk of a malignant tumour developing at that site. 
    • In the great majority of cases, no malignant neoplasms emerge
    • Certain forms of benign neoplasia also constitute precancerous conditions
    • Example – villous adenoma of the colon
    • Most benign neoplasms do not become cancerous
    Precancerous (Premalignant) Lesions.

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