AML Flashcards
What is AML?
It is a disease of the blood involving haematopoietic cells that are no longer capable of differentiating into mature haematopoietic cells. However, they are still able to proliferate.
It is an acute disease therefore symptoms develop quickly.
What is the mean age of diagnosis?
Usually affects adults in their 50-60s and male to female 5:3.
What are some of the subtypes of AML?
Considering the myeloblasts can differentiate to monocytes, megakaryocytes and erythrocytes, the subtypes is of AML include:
acute monocytic leukaemia, acute megakaryocytic leukaemia, and acute erythrocytic leukaemia (very very rare).
List some of the symptoms of AML
Symptoms of anaemia such as dyspnoea and fatigue. Increased risk of infections, increased risk of bleeding due to thrombocytopaenia. However, there is also the risk of DIC. The individual can present with hepatomegaly, splenomegaly, lymphadenopathy. There may be a headache or focal neurological signs if it has involved the CNS. There may be metabolic complications such as hyperkalaemia or hyperuricaemia from tumour lysis syndrome.
What investigations would you perform?
FBC, EUC, LFT, blood smear, bone marrow aspirate, bone marrow biopsy.
What is the diagnostic criteria for AML?
There has to be blasts >20% of total cellularity in the bone marrow biopsy or peripheral WCC.
The blasts must also be of myeloid lineage.
There are several genetic abnormalities that are diagnostic of AML regardless of blast count (they involve chromosome translocations).
The presence of myeloid sarcoma is also diagnostic of AML independent of blast count.
How do you differentiate AML from ALL via bone marrow aspirate and biopsy?
AML is characterised by the presence of myeloperoxidase, which forms structures known as Auer rods in the blasts on a blood smear.
ALL is characterised by the presence of TdT via nuclear staining. TdT is a DNA polymerase in lymphoblasts.
What would suggest good prognosis for AML?
Younger age, lack of other medical co-morbidities, no history of prior exposure to radiation therapy, no history of prior myelodysplasia.
Where is the preferred anatomical location for a bone marrow biopsy?
PSIS of the pelvis or the spine. If there has been prior radiation to the area, the sternum is an alternative for aspiration (not biopsy).
With respect to the genetic abnormalities that are diagnostic of AML independent of blast count, what are they?
T(8;21)
Inv(16)
T(15;17)
What are some implications of AML?
Anaemia, infections, bleeding, tumour lysis syndrome, hypokalaemia, hypercalcaemia, lactic acidosis, CNS leukaemia, ocular involvement, VTE, acute pulmonary failure.
