A 5-year-old comes to your office with 4 nontender, 2-cm, blue-red discolored nodules over both cheeks on the face. The day before, she was sledding down the local snow-covered hill. The most likely diagnosis is

A 5-year-old comes to your office with 4 nontender, 2-cm, blue-red discolored nodules over both cheeks on the face. The day before, she was sledding down the local snow-covered hill. The most likely diagnosis is

Epstein-Barr virus (EBV) infection is more likely to be associated with all the following malignancies EXCEPT

You are meeting with parents of a 10-year-old child who recently develops acute lymphoblastic leukemia (ALL). Which of the following is LEAST likely to increase the risk of CNS relapse in children with ALL?

A 6-year-old child complains of bilateral thigh pain, motor weakness, and some sensory deficits of both lower limbs; he has a history of bladder dysfunction over the past 2 weeks; MRI of the spinal cord shows a mass arising from the filum terminale and conus medullaris causing some pressure effect. A CNS tumor is suspected. Which of the following tumor is MOST likely arising in such site?

Childhood primary brain stem tumors are a heterogeneous group of tumors; the outcome usually depends on the tumor location. Which tumor, depending on the site of tumor, carries the worst prognosis?