Disorders of WBC & Leukemias - Free MCQ Practice Test with solutions, NEET

The image shows a chemoport which allows the patient to deliver drugs into a central line by himself/herself. It avoids the hassles and pain associated with repeated peripheral line insertion. The schematic diagram depicting the tip of the catheter in the Superior vena cava is shown below. The diagram on left shows insertion of a needle into the port by the patient himself.

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• Adult T-ccll leukemia is caused by HTLV-1 whereas the remaining diseases are caused by HHV-8.
• Diseases caused by HHV-8 infection include Kaposi sarcoma, multicentric Castleman disease (MCD), and primary effusion lymphoma (PEL), which occur primarily in patients with HIV infection.

• The DOC for management of APML is ATRA (Al Trans Retinoic acid)
• Use of tretinoin decreases the frequency of DIC but produces another complication known as APL differentiation syndrome.
• On administration of tretinoin the immature cells will mature. However due to adhesion of these differentiated neoplastic cells to pulmonary vasculature endothelium, the microcirculation of lungs is affected. Hence the features of respiratory distress develop in the patient.
• It occurs within 3 weeks of treatment and is characterised by fever, fluid retention, dyspnea, chest pain and pulmonary infiltrates.
• The mortality rale for APL Differentiation syndrome can approach 10% due to development of severe hypoxia and pericardial/pleural effusions.
• The best management for APL differentiation syndrome is administration of steroids.

5 year Survival rate after bone marrow transplantation 

Leukostasis is common with Acute Myeloid leukemia followed by ALL. It is rare in case of CLL or CML.

• WBC counts are in excess of > 100,000/cu.mm and leads to leukostatic plugging of the capillaries followed by endothelial damage to blood vessels.
• The clinical presentation of leukostasis indicates neurologic and pulmonary pathology.
• CNS leukostasis presents with stupor, headache and dizziness. Administration of 600 cGY of whole brain irradiation can protect against this complication along with anti-leukemic therapy
• The presence of dysnea, tachypnea and respiratory distress indicates pulmonary leukostasis.
• The mortality occurs due to respiratory failure, intracranial haemorrhage and coma.
• The low PO₂ is due to increased consumption of oxygen by leucocytes.
• It is common with Acute leukemia subtypes like Acute promyelocytic leukemia, acute monocytic leukemia and T cell type of ALL

Unfavourable prognostic factors for ALL

1. Extreme age group: <1 year or >10 years
2. Black males
3. TLC > 2 lac/cu.mm
4. Organomegaly
5. CNS Leukemia
6. L2 ALL, pre B cell and mature B cell ALL
7. Hypo-ploidy
8. 1(9:22) and 1(4:11) 
9. Remissions 14 days

• In juvenile chronic myeloid leukemia or juvenile chronic myelomonocytic leukemia, Philadelphia chromosome is negative and monosomy 7 is seen in 30% cases.
• Bone marrow aspirates show increased cellularity with predominance of granulocytic cells in all stages of maturation, megakaryocytes are normal to decreased. Hence low platelets are seen and need platelet transfusions.
• The disease has a fulminant, rapidly progressive course. Even with transplant there is 50% event free survival at 3 years.
• Management is supportive and needs packed RBC, platelet transfusions, infection management and allogenic stem cell transplantation.

Cell leukemia is responsive to chemotherapy with interferon alpha, pentostatin, or cladribine, with the latter being the usually preferred treatment.
Cell leukemia presents predominantly in older males. Typical presentation involves pancytopenia, although occasional patients will have a leukemic presentation. Splenomegaly is usual.

• The malignant cells appear to have “hairy" projections on light and electron microscopy and show a characteristic staining pattern with tartrate-resistant acid phosphatase.
• Bone marrow is typically not able to be aspirated, and biopsy shows a pattern of fibrosis with diffuse infiltration by the malignant cells. Patients with this disorder are prone to unusual infections, including infection by Mycobacterium aviumintracellulare, and to vasculitic syndromes.

Prognostic factor in acute lymphoblastic leukemia

• The exact chromosomal defect in Philadelphia chromosome is a translocation, in which parts of two chromosomes, 9 and 22, swap places. The result is that a fusion gene is created by juxta positioning the Abll gene on chromosome 9 (region q 34) to a part of the BCR (“breakpoint cluster region") gene on chrom osom e 22 (region q 11) . This is a reciprocal translocation, creating an elongated chromosome 9, and a truncated chromosome 22 (the Philadelphia chromosome).
• The significance of knowing this information is that this chromosome defect causes activation of an enzyme by the name of tyrosine kinase which provides energy to the cancer cells to divide uncontrollably.

In CML there will be rise in

• B12 level
• LDH level

And decreased levels of ALP.

The term agranulocytosis is used to communicate a more severe subset of neutropenia. Agranulocytosis refers to a virtual absence of neutrophils in peripheral blood. It is usually applied to cases in which the ANC is lower than 100/μL.

Allogeneic Stem Cell transplantation is currently the only curative therapy for CML and, when feasible, is the treatment of choice.

• Interferons when allogeneic SCT is not feasible, IFN-a therapy used to be the treatment of choice before Imatinib Mesylate became available.
• Only longer follow-up of patients treated with imatinib will prove whether IFN-a will still have a role in the treatment of CML. • Hydroxyurea, a ribonucleotide reductase inhibitor, induces rapid disease control.
• Allogenic bone marrow transplantation is treatment of choice for patients of CML.