Thread: Does a Palpated Abdominal Mass Indicate Pediatric Cancer?

While bathing her 2-year-old son, a mother feels a mass in his abdomen. A thorough medical evaluation of the child reveals aniridia, hypospadias, horseshoe kidney, and hemihypertrophy. Which of the following is the most likely diagnosis for this child?

a. Neuroblastoma
b. Wilms tumor
c. Hepatoblastoma
d. Rhabdomyosarcoma
e. Testicular cancer

[HIDE]The correct answer is b.Wilms tumor.

An abdominal mass is palpated in 85% of patients with Wilms tumor; abdominal pain is present in 40%, hypertension in about 60%, and hematuria in 12 to 24%. Because of the association of hemihypertrophy and aniridia with Wilms tumor, children with these findings should be followed with periodic physical examinations and abdominal sonograms, especially during their first 5 years. Wilms tumor and aniridia are associated with abnormalities in chromosome 11.

Neuroblastoma should also be considered in the differential diagnosis of abdominal mass, especially if fever, irritability, bone pain, limp, and diarrhea are present; in the case presented, however, the other features such as aniridia and horseshoe kidney make this diagnosis less likely than Wilms tumor.

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A 3-year-old child is suspected to have acute lymphoblastic leukemia. The family is meeting with the pediatric oncologist to review all laboratory data. They learn that the child’s initial white count is 12,000/mm3. Analysis of the bone marrow specimen demonstrates the leukemic line to be of the pre-B-cell variety with hyperdiploidy with more than 50 chromosomes. The radiologic evaluation demonstrates only a mediastinal mass. Which of the following features on presentation is likely to be of most concern to the treating oncologist?

a. Presence of a mediastinal mass
b. Hyperdiploidy with more than 50 chromosomes
c. The initial white blood cell count
d. The child’s age
e. The early pre-B-cell variety

[HIDE]The correct answer is a. Presence of a mediastinal mass.

Age less than 12 months or more than 10 to 15 years, a white blood cell count of 100,000/µL or higher, the presence at diagnosis of central nervous system leukemia, and the appearance of a mediastinal mass indicate a poorer prognosis for children who have acute lymphoblastic leukemia. The first two prognostic factors listed above (age and initial white blood cell count) are the most reliable. Hyperdiploidy with more than 50 chromosomes is a good prognostic factor for treatment with antimetabolic-based chemotherapy. Most of the children with these poor prognostic signs have the thymic (T cell) variety of the disease. In addition to the conventionally employed regimen of prednisone and vincristine, other chemotherapeutic agents should be administered. A smaller fraction of these patients with poor prognostic features can be expected to achieve long-term disease-free survival, and, once they relapse, many fail to go into remission despite aggressive chemotherapy. Bone marrow transplantation offers hope in some cases.

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A 2950-g (6.5-lb) black baby boy is born at home at term. On arrival at the hospital, he appears pale, but the physical examination is otherwise normal. Laboratory studies reveal the following: mother’s blood type A, Rh-positive; baby’s blood type O, Rh-positive; hematocrit 38%; reticulocyte count 5%. Which of the following is the most likely cause of the anemia?

a. Fetomaternal transfusion
b. ABO incompatibility
c. Physiologic anemia of the newborn
d. Sickle cell anemia
e. Iron-deficiency anemia


[HIDE]The correct answer is a. Fetomaternal transfusion.

The absence of a major blood-group incompatibility and the finding of a normal reticulocyte count argue strongly in favor of a recent fetomaternal transfusion, probably at the time of delivery. A Betke-Kleihauer stain for fetal hemoglobin-containing red cells in the mother’s blood would confirm the diagnosis. After birth, erythropoiesis ceases, and the progressive decline in hemoglobin values, reaching a nadir at 6 to 8 weeks of age, has been termed physiologic anemia of infancy. Iron-deficiency anemia can be seen in the term infant between 9 and 24 months of age when the iron stores derived from circulating hemoglobin have been exhausted and an exogenous dietary source of iron has not been provided. The manifestations of sickle cell disease do not appear until 4 to 6 months of life, coincident with the replacement of fetal hemoglobin with sickle hemoglobin.

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good cases
thanks alot