Week 5 Common Conditions Flashcards

Question

What are the risk factors of lymphoma?

Answer 1

Family history Certain infections Epstein-Barr Virus, HIV, HCV, HTLV, Herpes Virus-8, H. pylori Obesity Adipose tissue possesses endocrine & metabolic properties Iatrogenic immunosuppression e.g. anti-rejection therapy Autoimmune conditions: RA, SLE Exposure to ionizing radiation or mutagenic chemicals

Answer 2

One of the most common cancers in young adults Usually arises in a single node or chain of related nodes Spreads to nodes in close anatomical proximity. Characterised by a distinctive neoplastic cell, the Reed-Sternberg (RS) cell RS cells are large and binucleate; their presence is necessary for the diagnosis of HL Cytokines secreted by RS cells promote tumour growth

Answer 3

Lymphadenopathy Single or related group of superficial lymph nodes Nodes are typically painless, discrete and rubbery Cervical nodes usually affected first Spread: occurs to adjacent nodes (esp. mediastinal) Extranodal lymphoid involvement: uncommon Compressive features Occur secondary to nodal enlargement Dysphagia, dyspnoea, engorged neck veins, neural compression “B” symptoms Have prognostic significance Unexplained fever (>38C), drenching night sweats, unexplained wt loss (>10%) in preceding 6/12 Other constitutional symptoms: persistent fatigue, pruritis, anorexia

Answer 4

6th most common type of cancer in Australia increased incidence of NHLs: attributed to increased HIV infections Average age for diagnosis: 65 Although the disease can present at any age The term ‘ NHL’ refers to a diverse group of disorders B cell neoplasms (85% of tumours) T cell & NK cell neoplasms All types feature the neoplastic proliferation of lymphoid cells, but NOT the Reed-Sternberg form.

Answer 5

Lymphadenopathy Nodes are typically painless and discrete Usually originate in multiple sites: cervical, axillary, inguinal and femoral nodes commonly affected first Spread: occurs to non-contiguous nodes Extranodal lymphoid involvement: common Features reflect affected organs e.g. nasopharynx, GIT, bone, thyroid, testes, skin Compressive features Occur secondary to nodal enlargement ”B” symptoms & constitutional symptoms Can also exist in NHL

Answer 6

Used to be considered distinct entities, current knowledge suggests the distinction is vague Example: chronic lymphocytic leukaemia & small lymphocytic lymphoma Considered to have the same underlying disease process (neoplastic B cell proliferation) Current convention is to classify the disease based upon clinical presentation: If most cancer cells are in bone marrow + bloodstream = chronic lymphocytic leukaemia If most cancer cells are in lymph nodes, the disease is termed small lymphocytic lymphoma

Answer 7

Depends on the type of lymphoma and intent of treatment (curative vs. palliative) TREATMENTS INCLUDE Chemotherapy Radiotherapy Antibody therapy Corticosteroids Stem cell transplant PROGNOSIS ~75% of HL Pts can be cured NHL: prognosis depends greatly on subtype

Answer 8

Lymphoid malignancy of the bone marrow, characterised by the uncontrolled replication of plasma (immunoglobulin-secreting) cells

Answer 9

Accounts for 1.3% of all cancers in Australia | Rarely occurs before 40 yrs – peak age for diagnosis is 65

Answer 10

Chromosomal mutations play a key role Exact aetiology unknown Risk assoc. w/ radiation exposure Familial predisposition?

Answer 11

Myeloma cells: neoplastic plasma cells that produce excessive amounts of abnormal antibodies (M proteins) Result: decreased immunity, overcrowded marrow Antibody fragments (light-chains) are also produced and accumulate in tissues and organs Result: amyloidosis leads to renal failure Myeloma cells form discrete tumours (plasmacytomas) within bone Release of osteolytic cytokines destroys overlying cortical bone Result: radiographic ‘punched-out’ lesions (1-4cm in diameter)

Answer 12

Most commonly affects the vertebral column, ribs, skull, pelvis, femur, clavicle, scapula Risk for pathologic # Bone marrow biopsy: abundant myeloma cells Can comprise between 10 -90% of cells Large potential for spread: Lymph nodes Other bones Spleen, liver, kidneys lungs

Answer 13

Often insidious for years Bone destruction Bony pain, pathological # Hypercalcaemia - confusion, weakness, lethargy, polyuria, thirst, constipation Marrow overcrowding Decreased immunity - recurrent infections, fever Anaemia Overproduction of light-chains Deposited in kidneys as amyloid protein (toxic) Bence-Jones proteinuria in 99% of Pts Extraosseous plasmacytomas

Answer 14

Palliation: radiotherapy, chemotherapy

Answer 15

HIV is the pathogen responsible for acquired immunodeficiency syndrome (AIDS) It is a retrovirus and carries its genetic material as RNA (not DNA) The disease arose in Africa in the 1950s and has now spread throughout the world

Answer 16

At the end of 2016: 37 million people living with HIV worldwide, including 25, 000 Australians HIV notification rates are highest in the 25-44 age group Australian deaths from AIDS peaked in 1994 (953 deaths) It has now become a chronic disease due to the advent of anti-retroviral drugs

Answer 17

Predominantly through the exchange of body fluids (blood, semen) Not transmitted by fomites i.e. plates, cutlery, phones, drinking fountains Children can be infected: transplacental spread, blood spread during birth, via breast milk Occupational exposures e.g. nurses, pathology lab technicians Before rigorous screening measures were introduced, some contracted HIV from receiving blood transfusions or blood products

Answer 18

HIV infects and depletes immune cells which possess the CD4 glycoprotein Predisposes life-threatening infections and malignancies CD4 is found predominantly on T Helper (TH) lymphocytes Other CD4+ cells: some Tc lymphocytes, NK cells, macrophages, DCs Key viral enzymes: protease, reverse transcriptase Entry into cell HIV binds to CD4 receptor and chemokine co-receptor on the host cell Viral envelope and cell membrane fuse HIV RNA injected into the host cell’s cytoplasm Conversion of viral RNA HIV RNA converted to double-stranded DNA by the viral enzyme reverse transcriptase Viral DNA is integrated into the host cell’s DNA by the viral enzyme integrase Dormancy If host cell is NOT activated, viral DNA remains dormant (can be years) Activation If host cell is activated (by cytokines) the virus proliferates The viral enzyme protease modifies new virions Host cell death Release of new virions results in host cell lysis (necrosis) New virions free to infect other CD4-bearing (CD4+) cells

Answer 19

1. Acute infection 2. Chronic infection 3. Acquired immune deficiency syndrome

Answer 20

~50% of infected people experience acute illness soon after the initial exposure Due to the sudden increase of viruses in the host CLINICAL FEATURES Nonspecific flu-like symptoms, including: Fever, night sweats, fatigue, lymphadenopathy Sore throat, headache, photophobia, myalgia, arthralgia Diarrhoea, generalised maculopapular rash Most symptoms subside in 1-3 weeks, although chronic lethargy, depression & irritability can persist HIV antibodies may not be detectable for some months, however viral transmission is still possible

Answer 21

Relatively symptom-free +/- lymphadenopathy Can be 2 months  20 years before the onset of AIDS The median period is 10 years Virus multiplies but is only released sporadically CD4+ lymphocytes gradually decrease

Answer 22

AIDS can be diagnosed when various criteria are fulfilled Most common diagnostic criterion met: CD4+ lymphocyte count of <200 cells/mcL

Answer 23

Non-specific features Generalised lymphadenopathy Weight loss, wasting, nausea, fatigue, night sweats, fevers Neurological symptoms CNS affected more than PNS ``` HIV encephalopathy (AIDS dementia complex) Cognitive, behavioural, motor changes ``` Opportunistic infections Candidiasis, tuberculosis, widespread herpes simplex Rare infections Neoplasia e.g. non-Hodgkin’s lymphoma, Kaposi’s sarcoma Kaposi’s sarcoma: painless, red-purple lesions (can be on any part of the body)

Answer 24

ANTI-RETROVIRAL MEDICATIONS | Used in combination to inhibit viral replication and prevent progression to AIDS

Answer 25

``` MAINTAIN PHYSICAL & MENTAL HEALTH: Exercise, nutritional support Cessation of nicotine, alcohol & drug use Counselling Trace past partners ``` POST-EXPOSURE PROPHYLAXIS Must be implemented within 72 hours of potential exposure to HIV Short-term (28-day course) anti-retroviral treatment Reduces risk of seroconversion by up to 80% Available from sexual health clinics, hospital EDs PRE-EXPOSURE PROPHYLAXIS Approved by Therapeutic Goods Administration, but currently not on PBS