Pediatric Examination and Board Review (162 page)

18.
(B)
As mentioned, vWD is a group of heterogenous disorders with an underlying defect in vWF abundance or function. vWD is an autosomal dominant disorder that occurs equally in males and females in approximately 1% of the general population, making it the most common inherited bleeding disorder in the United States. Type 1 vWD, due to decreased vWF production, is the most common subtype of vWD, accounting for approximately 80% of cases. Types 2 and 3 vWD are much less common, the result of either a defect in the vWF protein or absent vWF production, respectively. Bleeding symptoms in patients with vWD are generally mild to moderate, and they predominantly involve mucocutaneous sites, with prolonged epistaxis, menorrhagia, and prolonged bleeding after dental procedures being common. Deep soft tissue hemorrhages and hemarthroses (intra-articular joint hemorrhages) that characterize patients with hemophilia are extremely rare in patients with vWD.

S
UGGESTED
R
EADING

Allen GA, Glader B. Approach to the bleeding child.
Pediatr Clin
North Am.
2002;49:1239-1256.

Blanchette V, Bolton-Maggs P. Childhood immune thrombocytopenic purpura: diagnosis and management.
Pediatr Clin North Am.
2008;55(2):393-420.

Casella JF, Bowers DC, Pelidis MA. Disorders of coagulation. In: McMillan JA, DeAngelis CD, Feigin RD, et al, eds.
Oski’s Pediatrics
:
Principles and Practice.
4th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2006.

Ewenstein BM. von Willebrand’s disease.
Annu Rev Med.
1997;48:525-542.

Furie B, Furie BC. Molecular basis of blood coagulation. In: Hoffman R, Benz EJ, Shattil SJ, et al, eds.
Hematology: Basic Principles and Practice.
5th ed. Philadelphia, PA: Churchill Livingstone; 2008.

Rodriguez NI, Hoots WK. Advances in hemophilia: experimental aspects and therapy.
Pediatr Clin North Am
. 2008; 55(2): 357-376.

CASE 93: A 3-YEAR-OLD GIRL WITH AN ABDOMINAL MASS

A mother brings in her 3-year-old daughter for evaluation after feeling a “lump” in her abdomen while giving her a bath. The child has been healthy and has no significant past medical history. She has had normal growth and development to date. There is no family history of significant medical problems.

On physical examination, the child is well appearing, laughing and playing on her mother’s lap. Her physical examination is notable for a large, firm mass palpable on the left side of her abdomen.

SELECT THE ONE BEST ANSWER

1.
Which of the following is the least likely cause of abdominal masses in children?

(A) teratoma

(B) neuroblastoma

(C) Wilms tumor

(D) renal cell carcinoma

(E) hepatoblastoma

2.
Which of the following clinical features is not associated with an increased incidence of Wilms tumor?

(A) hemihypertrophy

(B) renal insufficiency

(C) aniridia

(D) atrial septal defect

(E) hypospadias

3.
Children with Beckwith-Wiedemann syndrome are at increased risk for which of the following pediatric malignancies?

(A) medulloblastoma

(B) hepatoblastoma

(C) acute lymphoblastic leukemia

(D) retinoblastoma

(E) brainstem glioma

4.
Which of the following is the most common extracranial solid tumor in children?

(A) Wilms tumor

(B) hepatoblastoma

(C) neuroblastoma

(D) rhabdomyosarcoma

(E) non-Hodgkin lymphoma

5.
Which of the following age ranges has the highest incidence of Wilms tumor?

(A) 0-1 months

(B) 6-12 months

(C) 1-5 years

(D) 8-10 years

(E) 10-15 years

6.
Which of the following is the most common presentation of children with Wilms tumor?

(A) asymptomatic abdominal mass

(B) hypertensive crisis

(C) gross hematuria

(D) unilateral headache

(E) bone pain

7.
What percentage of Wilms tumors are bilateral (ie, present in both kidneys) at initial diagnosis?

(A) 1%

(B) 10%

(C) 20%

(D) 50%

(E) 90%

8.
Presenting features of children with neuroblastoma can include all of the following except

(A) periorbital ecchymoses

(B) unilateral miosis

(C) rapid, irregular eye movements

(D) elevated alpha-fetoprotein levels

(E) elevated vasoactive intestinal peptide levels and diffuse diarrhea

9.
Which of the following laboratory values is most likely to be abnormal in children with neuroblastoma?

(A) white blood cell count

(B) serum ALT and AST (alanine/aspartase aminotransferase) levels

(C) urine catecholamines

(D) PT

(E) platelet count

10.
Stage 4S neuroblastoma is characterized by disease at all of the following sites except

(A) liver

(B) bone marrow

(C) long bones

(D) skin

(E) adrenal gland

11.
Which of the following is the least common site of neuroblastoma metastatic disease?

(A) bones

(B) bone marrow

(C) CNS

(D) liver

(E) lymph nodes

12.
Which of the following syndromes is not associated with an increased risk of pediatric malignancies?

(A) ataxia-telangiectasia

(B) Li-Fraumeni syndrome

(C) Bloom syndrome

(D) osteogenesis imperfecta

(E) Down syndrome

13.
Which of the following neoplasms does
not
have an increased incidence in patients with type I neurofibromatosis?

(A) plexiform neurofibroma

(B) pheochromocytoma

(C) medulloblastoma

(D) optic glioma

(E) brainstem glioma

14.
Which of the following is the most common neonatal solid tumor?

(A) teratoma

(B) hepatoblastoma

(C) germinoma

(D) medulloblastoma

(E) retinoblastoma

15.
Which of the following tumors is least likely to arise in the anterior mediastinum?

(A) non-Hodgkin lymphoma

(B) germ cell tumor

(C) thymoma

(D) neuroblastoma

(E) teratoma

16.
Which of the following pediatric tumors is associated with increased beta-human chorionic gonadotropin (hCG) levels?

(A) neuroblastoma

(B) seminoma

(C) choriocarcinoma

(D) teratoma

(E) adrenal-cortical carcinoma

ANSWERS

1.
(D)
The differential diagnosis of pediatric abdominal masses includes neoplastic and nonneoplastic causes. Potential pediatric neoplasms that can present as abdominal masses include germ cell tumors, neuroblastomas, Wilms tumors, lymphomas, and rhabdomyosarcomas, among others. Renal cell carcinoma can occur in children but is extremely rare. Other nonneoplastic causes of palpable pediatric abdominal masses to be considered include impacted stool, distended bladder, intraabdominal abscesses, ovarian cysts, pyloric stenosis, enlarged kidneys secondary to polycystic kidney disease, hydronephrosis, or renal vein thrombosis.

2.
(D)
Several syndromes and physical features are associated with an increased incidence of Wilms tumor. Beckwith-Wiedemann syndrome, WAGR syndrome (
W
ilms tumor,
a
niridia,
g
enitourinary malformations, and mental
r
etardation), and Denys-Drash syndrome (renal failure, pseudohermaphroditism, and Wilms tumor) are associated with an increased incidence of Wilms tumor. Patients with hemihypertrophy or aniridia also have an increased risk and should be screened regularly for abdominal malignancies. Patients with aniridia associated with a chromosome 11p13 deletion have up to a 50% incidence of Wilms tumor by 4 years of age. There is no increased incidence in Wilms tumor associated with the presence of cardiac defects.