You are here

Essential thrombocythaemia B067

Last amended 
29 June 2015
Current RMA Instruments:
Reasonable Hypothesis SOP
15 of 2013
Balance of Probabilities SOP
16 of 2013
Changes from Previous Instruments:

SOP Bulletin 164

 ICD Coding:
  • ICD-9-CM Codes: 238.71
  • ICD-10-AM Codes: D47.3

This is a blood disorder in which the platelets (thrombocytes) are excessive in number.  The adjective ‘essential’ implies that there is no known cause for this type of condition, that is idiopathic.  Note that whilst this is classified as a neoplasm it is not a malignant neoplasm.

A platelet is designed to plug abnormal holes in the blood vessels in conjunction with fibrin provided via the coagulation factor cascades.  As such an increase in platelets leads to abnormal thrombosis (clots) and associated haemorrhages. However this condition can be asymptomatic for years and picked up incidentally with a routine full blood count.

Is specific diagnostic evidence required to apply the SOP?Yes.

This diagnosis is complex and is a diagnosis of exclusion of secondary causes. Hence an opinion from a specialist haematologist is necessarily required in addition to copies of reports of a full blood count, and a peripheral blood smear.

Are there sub-factors that require specific information? – No.
Additional diagnoses covered by SOP
  • Essential haemorrhagic thrombocythaemia
  • Idiopathic thrombocythaemia
  • Essential thrombocytosis
Conditions excluded from SOP
  • Secondary thrombocythaemia
Unconfirmed diagnosis

If, after applying the above information, you are unable to confirm the diagnosis, you should then:

  1. seek medical officer advice about further investigation, or
  2. re-encode the condition, if appropriate.

The following investigations may be useful in establishing the diagnosis:

  • Report from treating specialist