Acute Lymphoblastic Leukemia (ALL) Treatment Phases

Acute Lymphoblastic Leukemia (ALL)

• High-risk cases receive daunomycin at weekly intervals
• Remission is defined as less than 5% blasts in the marrow and a return of neutrophil and platelet counts to near-normal levels after 4-5 weeks of treatment
• Treatment consists of three phases:
  • Induction of remission (4 weeks)
  • Consolidation intensification phase (14-28 weeks)
  • Maintenance therapy (2-3 years)

Types of Relapse

• Bone marrow relapse: most common and serious, treated with bone marrow transplantation following intensive chemotherapy
• CNS relapse: manifests as increased intracranial tension, convulsions, and cranial nerve paralysis, treated with intrathecal medication, craniospinal irradiation, and systemic chemotherapy
• Testicular relapse: painless swelling of one or both testes, treated with systemic chemotherapy and local irradiation

Lymphomas

• Third most common cancer in children
• Includes non-Hodgkin lymphomas and Hodgkin disease
• Non-Hodgkin lymphoma:
  • Malignant clonal proliferation of primarily T or B-lymphocytes
  • Increased frequency in children with immunodeficiency diseases
  • Subtypes:
    • Small non-cleaved cell lymphoma (Burkitt and non-Burkitt subtypes, B-cell origin)
    • Lymphoblastic lymphoma: T-cell type
    • Large cell NHL: T-cell, B-cell or indeterminate cell origin
• Clinical manifestations:
  • Abdominal lymphoma: presents with abdominal mass or distention, nausea, vomiting, or change in bowel habits
  • Mediastinal lymphoma: presents with mediastinal mass, pleural effusions, or respiratory distress
  • Head and neck regions: painless, firm lymph nodes
  • Involvement of other systems:
    • Bone marrow: anemia or pancytopenia
    • CNS: manifestations of increased intracranial pressure and cranial nerve paralysis

Hodgkin Lymphoma

• Incidence: not common in children, occurs in late childhood to adolescence, males more affected than females
• Pathologic classification:
  • Nodular sclerosing type
  • Mixed cellularity type
  • Lymphocytic predominant type
  • Lymphocytic depletion type: least common and least favorable
• Clinical manifestations:
  • General symptoms and signs: lethargy, anorexia, unexplained fever, night sweating, and weight loss
  • Painless enlargement of lymph nodes
  • Mediastinal syndrome: a common presentation

Wilms Tumor (Nephroblastoma)

• Embryonal tumor of the kidney
• May arise in one or both kidneys
• Most common genitourinary malignancy affecting children, accounts for about 6% of childhood malignancies
• Occurs in equal frequency in boys and girls, most commonly between 2-5 years
• Triphasic appearance, with varying proportions of three cell types (blastemal, stromal, epithelial)
• Clinical features:
  • Asymptomatic abdominal mass usually discovered accidentally by parents or routine abdominal examination
  • Associated symptoms: abdominal pain, fever, and hematuria
  • Hypertension may occur in 25% of cases
  • Bilateral Wilms tumor may occur

Neuroblastoma

• Embryonal tumor derived from neural crest cells that form the adrenal medulla and the sympathetic nervous system
• Third most common solid tumor of childhood
• Age incidence: 90% are less than 5 years
• Etiology: unknown, may be attributed to environmental and genetic factors
• Pathology: ranges from undifferentiated small round cells (neuroblastoma) to tumours containing mature ganglion cells (ganglioneuroblastoma or ganglioneuroma)
• Clinical manifestations:
  • Abdominal mass: commonest presentation, hard, irregular, and non-tender mass located in right or left upper quadrant
  • Posterior mediastinal mass: may present with mediastinal syndrome, progressive dyspnea, dysphagia, and stridor
  • Proptosis: proptosis may be unilateral or bilateral
  • Multiple skin nodules in infancy: firm and purple in color, mainly occur in infants under the age of 6 months
  • Spinal cord compression: may cause paralysis and bowel or bladder dysfunction