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Primary Myelofibrosis B068

Document
Last amended 
21 November 2019
Current RMA Instruments
Reasonable Hypothesis SOP
17 of 2013
Balance of Probabilities SOP
18 of 2013
Changes from previous Instruments

SOP Bulletin 164

ICD Coding
  • ICD-9-CM Codes: 238.72, 289.8
  • ICD-10-AM Codes: D47.4
Brief description

Primary myelofibrosis is one of the chronic myeloproliferative disorders, in which there is chronic proliferation of types of myeloid cells in the bone marrow.  A feature of this condition is the development of bone marrow fibrosis (due to proliferation of fibroblasts).  This leads to impaired production of red blood cells and severe anaemia. Blood cell production then shifts to the spleen and liver, leading to enlargement of those organs (splenomegaly / hepatomegaly).

The adjective ‘primary’ implies that there is no known secondary cause for this type of condition, i.e., that is it is idiopathic.  This is reflected in the SOP, which has no causal factors.  This condition is classified as a neoplasm, but it is not a malignant neoplasm.

Confirming the diagnosi

This diagnosis is complex and is based on clinical and laboratory findings.  Bone marrow biopsy is generally necessary to demonstrate marrow fibrosis and exclude other causes such as malignant bone marrow infiltration.  Genetic testing for gene mutations may also be performed.

The relevant medical specialist is a haematologist.

Additional diagnoses covered by SOP
  • Agnogenic myeloid metaplasia
  • Chronic idiopathic myelofibrosis
  • Myelofibrosis with myeloid metaplasia
Conditions excluded from SOP
  • Acute myelofibrosis
  • Chronic myeloid leukaemia*
  • Essential thrombocythaemia*
  • Myelodysplastic syndrome*
  • Polycythaemia vera*

* another SOP applies

non-SOP condition

Clinical onset

The usual presentation is with severe fatigue (due to anaemia).  The condition may also first present with symptoms or signs of an enlarged spleen.  It may also be found following detection of an enlarged liver or abnormal blood test findings.

Clinical worsening

The only SOP factor is for inability to obtain appropriate clinical management.  Treatment varies with the presentation and stage of disease, but disease modifying treatment is available and appropriate in some cases, particularly in the form of transplantation.