Page 345 - Concise Pathology for Exam Preparation ( PDFDrive )

330 SECTION II Diseases of Organ Systems

TABLE 12.16. Comparison between CML and myelofibrosis

Features CML Myelofibrosis
Clinical features
• Splenomegaly Moderate to marked Marked
• Fever Common Uncommon
Laboratory investigations
• RBCs • Marked anaemia Slight to moderate anaemia
• Mild poikilocytosis Prominent poikilocytosis with
tear-drop cells
• WBCs Marked increase; 20–50 3 10 /L Normal, raised or low; when
9
raised not more than 50 3
9
10 /L
• Nucleated red cells Few if any Numerous
• LAP Low Normal, raised or reduced
• Bone marrow aspiration Hyperplastic marrow with absence Dry tap without marrow frag-
of fat spaces ments
• Chromosomal analysis Philadelphia-positive Philadelphia-negative

Q. Write briefly on myelodysplastic syndrome (MDS).

Ans. The myelodysplastic syndromes are clonal disorders characterized by ineffective
haematopoiesis and production of defective haematopoietic cells of erythroid, myeloid and
megakaryocytic series. These patients are at increased risk of developing acute leukaemias.

Aetiology
In most cases the cause is unknown (idiopathic MDS); however, exposure to radiation,
cancer chemotherapy, pesticides and ageing are implicated.

Clinical Features

• Failure of bone marrow to produce normal blood cells leads to anaemia, leucopenia and
thrombocytopenia.
• Extramedullary haematopoiesis may occur leading to hepatomegaly and splenomegaly.

Classification (see Table 12.17)

TABLE 12.17. Classification of MDS
Category Criteria
Refractory anaemia (RA) • Anaemia with reticulocytopenia
• Normal or hypercellular bone marrow with dyserythropoiesis; blasT cells
, 5%
Refractory anaemia with • Same as refractory anaemia with ringed sideroblasts (. 15% of nucleated mar-
sideroblasts (RARS) row cells)
Refractory anaemia with • Cytopenia of two or more cell lines with morphologic abnormalities of blood cells
excess blasts (RAEB) • Hypercellular bone marrow with blasts 5–20% of nucleated marrow cells
Refractory anaemia with • Cytopenia of two or more cell lines with morphologic abnormalities of blood
excess blasts in transfor- cells and . 5% blasts in peripheral smear
mation (RAEBT) • Hypercellular bone marrow with blasts 20–30% of nucleated marrow cells
• Auer rods in granulocyte precursors
Chronic myelomonocytic • Cytopenia of two or more cell lines with morphologic abnormalities of blood
leukaemia cells and absolute monocytosis
• Significant increase in marrow monocyte precursors

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