Neoplasms and Acute Lymphocytic Leukemia (ALL)

• A neoplasm refers to a "new growth" characterized by abnormal proliferation unaffected by normal growth-control mechanisms.
• Neoplasms can be benign, where growth is limited, or malignant (cancerous), where growth is unlimited.

Causes of Neoplastic Growth

• The causes of neoplastic growth are largely unknown.
• Most childhood cancers involve genetic markers, triggers, or predispositions.
• The somatic mutation theory suggests that the accumulation of mutations leads to neoplastic transformation.
• Neoplastic cells cannot revert to a normal state due to intrinsic genomic changes.
• Intrinsic and extrinsic factors or inherited tendencies combined with environmental factors contribute to neoplasm development.
• Oncogenic viruses like HPV can alter DNA or RNA, leading to tumor growth.

Acute Lymphocytic Leukemia (ALL)

• ALL accounts for 75% of leukemias and involves lymphoblasts (immature lymphocytes).
• Rapid proliferation of immature lymphocytes decreases the production of red blood cells (RBCs) and platelets.
• Abnormally proliferating cells are so immature they are identifiable as immature blast cells.
• The highest incidence of ALL occurs in children aged 2 to 6 years.

Assessment of ALL

• Manifestations of ALL include decreased RBC production (anemia), leading to pallor, low-grade fever, and lethargy.
• Low thrombocyte counts result in petechiae and bleeding from mucous membranes, causing easy bruising.
• Spleen and liver enlargement due to infiltration of abnormal cells causes abdominal pain, vomiting, and anorexia.
• Bone and joint pain occur due to invasion of abnormal lymphocytes in the bone periosteum.
• CNS invasion can lead to headaches or an unsteady gait.
• Generalized swelling of lymph nodes is observed, which is usually painless.
• Elevated leukocyte counts with cells stopped at the blast cell stage can be seen.
• Low platelet counts and hematocrit levels are typical; RBCs present are normocytic and normochromic but few.
• Lumbar puncture may reveal blast cells in the cerebrospinal fluid (CSF).
• A bone marrow aspiration identifies the type of WBC involved, documenting the leukemia type.

Therapeutic Management of ALL

• 95% of children with ALL achieve a first remission.
• Relapse reduces long-term survival chances and may require bone marrow transplantation.
• The remission induction drug regimen includes vincristine, prednisone or dexamethasone, L-asparaginase, and doxorubicin, given over four weeks.
• Intrathecal methotrexate is used to eradicate leukemic cells in the cerebrospinal fluid.
• Cranial radiation is rarely used today.
• maintenance chemotherapy eliminates any remaining leukemic cells.
• Common maintenance therapy uses daily mercaptopurine, weekly methotrexate, sporadic vincristine and prednisone, and intrathecal methotrexate for 2-3 years.
• Complications include CNS, renal, and reproductive system disorders.

Acute Myeloid Leukemia (AML)

• AML involves the overproliferation of granulocytes (neutrophils, basophils, and eosinophils).
• AML is most common in adults, accounting for about 20% of childhood leukemias.
• The frequency of AML increases in late adolescence.
• Children with AML have similar symptoms to those with ALL which are found on assessment.
• Comprehensive history and physical examination, focusing on local or systemic infections, is warranted.
• Diagnosis is established by bone marrow aspiration and biopsy.
• Chemotherapy is used to induce remission.
• A common drug regimen includes cytarabine (Ara-C), etoposide (VePesid), and daunorubicin (DaunoXome).
• Full remission may take 1-2 months.
• Bone marrow transplantation may ensure sustained remission after initial remission.

Hodgkin's Disease

• Lymphocytes proliferate in the lymph glands, and special Reed-Sternberg cells develop.
• The etiology of Hodgkin disease is unknown.
• Rarely are children under 7 years of age affected, with incidence increasing greatly during adolescence and young adulthood.
• Metastasis occurs through lymphatic channels, spreading to the lung, liver, and bone marrow in late-stage, untreated disease.
• The condition usually starts with an enlargement of one painless and enlarged lymph node.
• Assessment findings include anorexia, malaise, night sweats, weight loss, and fever.
• Diagnosis is confirmed by lymph node biopsy.
• Clinical staging involves bone marrow analysis, liver function tests, chest and abdominal computed tomography (CT) or MRI scans, lymphangiography, and abdominal biopsy.
• Chest CT scans reveal enlarged mediastinal nodes, and abdominal CT scans reveal enlarged abdominal lymph nodes.
• Positron emission tomography-computed tomography (PET-CT) is used to stage and monitor the Hodgkin disease treatment.

Therapeutic Management of Hodgkin's Disease

• Treatment involves radiation therapy as well as combination chemotherapy using cyclophosphamide, vincristine, procarbazine, and prednisone.

Non-Hodgkin's Lymphoma

• Non-Hodgkin’s lymphoma refers to malignant disorders of the lymphocytes (B or T cells) that occur in a number of forms.
• Metastatic spread to the CNS may occur early in the disease.
• The common age of occurrence is 5 to 15 years.
• Inguinal nodes may be the first involved.
• If mediastinal lymph glands are swollen, a child may have a cough or chest "tightness."
• Children may notice abdominal pain, diarrhea or constipation, and a mass may be palpable on examination.
• Diagnosis is established via biopsy of the affected lymph nodes and bone marrow.
• Systemic chemotherapy is similar to that used for ALL.
• An induction phase puts the child into remission or where no tumor can be detected by clinical examination.
• A maintenance phase lasts up to 2 years.
• The common drug regimen used is cyclophosphamide, doxorubicin (Adriamycin), vincristine (Oncovin), and prednisone (CHOP therapy).
• Intrathecal chemotherapy may be included because of the tendency for non-Hodgkin lymphoma to invade the CNS.
• Frequent blood analysis is required to monitor for electrolyte imbalances.
• Allopurinol may be added to prevent uric acid accumulation and blocking of kidney tubules.