The parents of a 13-month-old boy are contacted by a local social agency because the day care they are using has reported them for
suspected child abuse. The abuse was suspected because the day care personnel thought that the toddler had "too many bruises." The
parents deny the abuse, and promptly arrange to have their child seen by the chairman of the pediatrics department in a clinic run by a
university medical center. On physical examination, the child is noted to have multiple large bruises on his legs, arms, and buttocks. No skin
abrasions are seen, and no "pattern marks" (suggestive of being hit by an object such as a belt buckle or rod) are seen. A blood smear isunremarkable. PTT is prolonged, and PT and bleeding times are normaI.

Which of the following is the most likely diagnosis?
A. Acute myelogenous leukemia
B. Disseminated intravascular coagulation
C. Hemophilia
D. Thrombocytopenia
E. Von Willebrand's disease