Should haematology (hematology) or gastroenterology manage polycythaemia (polycythemia)?

Management of Polycythemia: Hematology vs. Gastroenterology

Polycythemia should be primarily managed by hematology specialists, as it is a hematological malignancy in the myeloproliferative neoplasm family requiring specialized expertise in blood disorders. 1, 2

Rationale for Hematology Management

Classification and Nature of Disease

• Polycythemia vera (PV) is classified as a chronic myeloproliferative disorder, a category of hematological malignancies 3
• It is characterized by clonal erythrocytosis and often involves other blood cell lines (leukocytosis, thrombocytosis) 4
• The disease involves bone marrow hyperplasia and abnormal megakaryocytic proliferation, requiring hematological expertise for diagnosis and management 3

Diagnostic Approach

• Diagnosis requires specialized hematological testing:
  • JAK2 mutation testing (V617F or exon 12) - present in >95% of PV cases 1
  • Bone marrow aspirate and biopsy to confirm diagnosis and exclude other myeloproliferative disorders 1
  • Serum erythropoietin levels to distinguish primary from secondary causes 1

Treatment Expertise

• Management requires specialized hematological interventions:
  • Therapeutic phlebotomy to maintain hematocrit <45% 3, 1
  • Risk stratification for thrombotic complications 3
  • Cytoreductive therapy with agents like hydroxyurea, interferon-α, or ruxolitinib 3, 5
  • Monitoring for disease progression to myelofibrosis or acute leukemia 1, 4

Role of Gastroenterology

While gastroenterologists are not the primary specialists for managing polycythemia, they may have a consultative role in specific situations:

• Evaluation of unexplained iron deficiency in patients with polycythemia 3
• Investigation of abnormal tissue transglutaminase (TTG) antibodies that may require endoscopy and small bowel biopsy 3
• Management of splanchnic vein thrombosis, which can occur in PV patients 6
• Consultation for hepatic involvement in cases with iron overload 3

Collaborative Management Approach

The optimal approach involves:

1. Primary management by hematology specialists who direct the overall treatment plan, including:

   • Diagnosis confirmation through specialized testing
   • Risk stratification
   • Phlebotomy protocols
   • Cytoreductive therapy decisions
   • Long-term monitoring for disease progression

2. Gastroenterology consultation when specific gastrointestinal issues arise:

   • Investigation of iron deficiency requiring endoscopy
   • Management of splanchnic vein thrombosis
   • Evaluation of hepatic complications

Common Pitfalls to Avoid

• Delayed diagnosis: Failing to refer patients with suspected polycythemia to hematology can delay proper diagnosis and treatment 1
• Inadequate monitoring: Polycythemia requires regular monitoring for thrombotic complications and disease progression that is best managed by hematology specialists 1
• Overzealous phlebotomy: In secondary polycythemia, excessive phlebotomy can increase stroke risk and requires specialized hematological expertise 1
• Missed secondary causes: While investigating polycythemia, secondary causes like gastrointestinal bleeding should be considered but within the context of a hematology-led diagnostic approach 3, 7

In conclusion, while multidisciplinary care may be beneficial in certain cases, the primary responsibility for managing polycythemia rests with hematology specialists due to the nature of the disease as a myeloproliferative neoplasm requiring specialized hematological expertise.