Malignancies Flashcards
What is leukaemia?
Malignant progressive disease in which bone marrow and blood forming organs produce increased numbers of immature or abnormal leukocytes (suppressing other blood cells such as erythrocytes). Leukocytes are any WBC.
What are lymphoid and myeloid cells?
.
What are the four types of leukaemia?
- LYMPHOID (lymphocytes) or MYELOID (granulocytes, erythrocytes, monocytes, megakaryocytes)
- ACUTE (rapid increase in the number of immature cells) or CHRONIC (excessive build-up of relatively mature WBCs but are MONOCLONAL in origin)
What are the risk factors for AML and ALL? (x4)
Radiation, viruses, chemotherapy drugs, genetic (associated more with ALL Down’s, neurofibromatosis type 1, Fanconi’s anaemia, xeroderma pigmentosum)
What is the pathophysiology of ALL and AML?
Lymphoblasts in ALL and myeloblasts in AML, arrested during development with cytogenic abnormalities, chromosomal abnormalities and gene mutations, undergo malignant transformation and proliferation with subsequent replacement of normal marrow, leading to bone marrow failure, reduced haematopoiesis and infiltration into other tissues.
What is the epidemiology of ALL: Common? Age?
Most common malignancy of childhood. 2-5 years old and also in elderly.
What is the epidemiology of AML: Common? Age?
Most common of the acute leakaemias in adults. Increased incidence with age.
What is the epidemiology of CLL: Age? Gender? Ethnicity?
Affects patients over 50. More common in males. Rare in Asians.
What is the epidemiology of CML: Age? Gender?
Increases with age. 40-60 years old. More common males.
What are the signs and symptoms of AML and ALL? (x3 and x7) Differentials? (x4 and x2)
- BONE MARROW FAILURE: anaemia, bleeding, opportunistic infections (from reduced WCCs). Anaemia can manifest with murmurs
- ORGAN INFILTRATION: tender bones, lymphadenopathy, hepatosplenomegaly, meningeal involvement (headaches, visual disturbances, nausea), skin infiltrations, painless unilateral testicular enlargement, pleural effusions
- ALL: if there is proliferation of T-cells, patients present with mediastinal compression. More likely to also see retinal haemorrhage/papilledema, leukemic infiltration in anterior chamber of eye and cranial nerve palsies
- AML: associated more with gum mucosa bleeding and swelling (hypertrophy), and DIC
! What are the investigations for ALL? (x6) Diagnosis?
- FBC: normocytic anaemia with low reticulocyte count, low platelets, leucocytosis (remember this means high numbers), neutropenia, raised uric acid (from high cell turnover), high LDH
- BLOOD FILM: lymphoblasts, low reticulocytes
- BONE MARROW ASPIRATE/TREPHINE BIOPSY: hypercellularity with at least 20% lymphoblasts is diagnostic
- IMMUNOPHENOTYPING: use antibodies to identify cell surface antigens. This can determine whether leukaemia has lymphoid or myeloid lineage and therefore differentiate between ALL and AML respectively.
- CYTOGENETICS: karyotyping; identify CHROMOSOMAL abnormalities or translocations
- CYTOCHEMISTRY: B- and T-lineages show up with PAS stain and acid phosphatase respectively
! What are the investigations for AML? (x6) Diagnosis?
- Differences with ALL highlighted in CAPITALS
- FBC: MACROcytic anaemia with low reticulocyte count, low platelets, leucocytosis (remember this means high numbers), neutropenia, raised uric acid (from high cell turnover), high LDH. MAY SEE DIC
- BLOOD FILM: HYPERGRANULATED MYELOBLASTS and AUER RODS (crystallisation of granules in granulocytes), low reticulocytes
- BONE MARROW ASPIRATE/TREPHINE BIOPSY: hypercellularity with at least 20% myeloblasts is diagnostic
- IMMUNOPHENOTYPING: classify lineage of abnormal clones
- CYTOGENETICS
- CYTOCHEMISTRY: myeloblasts granules are positive for Sudan black, chloroacetate esterase and myeloperoxidase, monoblasts are positive for butyrate esterase
What investigations are used to assess symptoms of ALL and AML? (x3)
- LP and CSF analysis: for CNS involvement
- CXR: mediastinal lymphadenopathy, mediastinal compression and lytic bone lesions
- Bone radiographs: mottled appearance with ‘punched-out’ lesions from leukemic infiltration.
What is the aetiology and pathophysiology of CLL? (x3)
- Malignant cells accumulate as a result of their inability to undergo apoptosis. This is associated with overexpression of BCL2 and Fas-inhibitory molecules, arising from chromosomal changes (e.g., trisomy 12, 11q and 13q deletions) and overexpression of certain microRNAs (that modulate the expression of genes post-transcription).
- CLL cells can infiltrate the lymphatic system and haematopoietic organs leading to hepatosplenomegaly, lymphadenopathy and bone marrow suppression
- CLL cells also involved in initiating antibody production by normal B cells, leading to autoimmune reactions such as autoimmune haemolytic anaemia and ITP
What is the aetiology and pathophysiology of CML? Which cell type is most commonly affected?
- Associated with ionising radiation; not hereditary
- Malignant cells accumulate as a result of proliferation of stem cells. This is associated with chromosomal translocation t(9;22) resulting in Philadelphia chromosome and subsequent fusion of BCR and ABL genes. This results in transcription of a BCR-ABL protein which drives cell replication by increased tyrosine kinase activity.
- There is proliferation of mostly granulocytic stem cells.