Oncology

Question 1

Leukemia

Answer 1

malignancy of lymphocytic or myeloblastic origin. Most common childhood malignancy.

97% of cases are acute leukemia (ALL more than AML).

ALL is most common in male white kids btw 2 and 5 years old.

AML is seen in black kids more throughout childhood

Associated with Down Syndrome, Fanconi anemia, prior radiation, SCID, and congenital bone marrow failure states

ALL is the most common childhood malignancy followed by CNS tumors and lymphomas

Question 2

History and exam for leukemia

Answer 2

1) Symptoms are abrupt in onset. They are initially nonspecific (anorexia, fatigue) and are followed by bone pain with limp or refusal to bear weight, fever (from neutropenia), anemia, ecchymoses, petechiae, and/or HSM
2) CNS mets may be associated with HA, vomiting, and papilledema
3) AML can present with a chloroma, a greenish soft-tissue tumor on skin or spinal cord

Question 3

Dx of leukemia

Answer 3

1) CBC, coagulation studies, and blood smear which shows high numbers of blasts (lymphoblasts found in 90% of cases). WBC counts can be low, normal or high
2) A bone marrow sample for immunophenotyping (TdT assay and a panel of monoclonal antibodies to T and B cell antigens) and genetic analysis help confirm the dx. The dx is made if bone marrow is hypercellular with increased lymphoblasts
3) CXR to rule out mediastinal mass

Question 4

Tx of leukemia

Answer 4

1) Chemo based, including induction, consolidation and maintenance phases
2) Tumor Lysis Syndrome (watch out for it at onset of any chemo regimen): HyperK, HyperP, Hyperuricemia is common prior to and during initiation of treatment. Treat with fluids, diuretics, allopurinol, urine alkalinization and reduction of phosphate intake. Steroids are contraindicated bc they can precipitate tumor lysis syndrome

Question 5

Neuroblastoma

Answer 5

An embryonal tumor of neural crest origin. More than half of patients are less than 2 years of age and 70% have distant mets at presentation

Associated with neurofibromatosis, Hirschsprung’s and N-myc oncogene

Question 6

History and exam for neuroblastoma

Answer 6

1) lession sites are most commonly abdominal, thoracic, and cervical
2) Symptoms may vary with location and may include a nontender abdominal mass (may cross midline*), Horner’s, HTN, or cord compression (from a paraspinal tumor)
3) Patients may have anemia, FTT, and fever
4) More than half will have mets at presentation. Signs include bone marrow suppression, proptosis, hepatomegaly, subQ nodules, and opsoclonus/myoclonus

Question 7

Dx of neuroblastoma

Answer 7

1) CT scan; FNA of tumor. Histologically appears as small, round, blue tumor cells with a characteristic rosette pattern
2) Elevated 24h urinary catecholamines (VMA and HVA)
3) Bone scan and bone marrow aspirate
4) CBC, LFTs, coagulation panel, BUN/Cr

Question 8

Tx of neuroblastoma

Answer 8

Local excision plus postsurgical chemo and/or radiation

Question 9

Wilm’s Tumor

Answer 9

A renal tumor of embryonal origin that is most commonly seen in children 2-5 years of age. Associated with Beckwith-Wiedemann Syndrome (hemi-hypertrophy, macroglossia, visceromegaly), neurofibromatosis, and WAGR syndrome (Wilms, Aniridia, GU abnormalities, mental Retarded)

Question 10

History and exam for Wilm’s

Answer 10

1) Presents as an ASx, nontender, smooth abdominal mass that does not usually cross the midline**
2) Abdominal pain, fever, HTN, and microscopic or gross hematuria are seen

Question 11

Dx of Wilm’s

Answer 11

1) CBC, BUN, Cr and UA
2) Abdominal US
3) CT scans of the chest and abdomen are used to detect mets

Question 12

Tx of Wilm’s

Answer 12

Local resection and nephrectomy with postsurgical chemo and radiation depending on stage and histology

Question 13

Ewing’s Sarcoma

Answer 13

1) Origin: Sarcoma (neuroectoderm); associated with chromosome 11:22 translocation
2) Epi: Commonly seen in white male adolescents
3) History and exam: Local pain and swelling, systemic symptoms (fever, anorexia, fatigue) are common
4) Location: Midshaft of long bones (femur, pelvis, fibula, humerus)
5) Dx: Leukocytosis, high ESR, Lytic bone lesion with onion skin periosteal reaction on plain XR
6) Tx: Local excision, chemo, radiation

Question 14

Osteosarcoma

Answer 14

1) Origin: Osteoblasts (mesenchyme)
2) Epi: Commonly seen in male adolescents
3) History and exam: Local pain and swelling. Systemic symptoms rare
4) Location: Metaphyses of long bones (distal femur, proximal tibia, prox humerus). Mets to lungs in 20%
5) Dx: Increased Alk Phos. Sunburst lytic bone lesions. Chest CT to rule out pulmonary mets
6) Tx: Local excision, chemo