A 4-year-old boy is brought to the office by his mother due to bruising. Over the last month, he has developed multiple bruises along his chest, back, and legs. The patient normally is very active and enjoys playing outside with his older siblings. However, he has been more tired than usual and takes longer naps. He has also had a poor appetite. This past week, his gums have been oozing blood during tooth brushing. The patient takes no daily medications. Last year, he had a tonsillectomy with no complications. His paternal uncle has hemophilia. Vital signs are normal. The patient appears pale and tired. Examination shows a few hematomas on the buccal mucosa. Scattered bruises are present on the shins, anterior chest, and back. Nontender anterior cervical lymphadenopathy is palpated bilaterally. Abdominal examination shows hepatosplenomegaly. No joint swelling is present. Further evaluation of this patient would most likely reveal a deficiency in which of the following?

Question

A 4-year-old boy is brought to the office by his mother due to bruising.  Over the last month, he has developed multiple bruises along his chest, back, and legs.  The patient normally is very active and enjoys playing outside with his older siblings.  However, he has been more tired than usual and takes longer naps.  He has also had a poor appetite.  This past week, his gums have been oozing blood during tooth brushing.  The patient takes no daily medications.  Last year, he had a tonsillectomy with no complications.  His paternal uncle has hemophilia.  Vital signs are normal.  The patient appears pale and tired.  Examination shows a few hematomas on the buccal mucosa.  Scattered bruises are present on the shins, anterior chest, and back.  Nontender anterior cervical lymphadenopathy is palpated bilaterally.  Abdominal examination shows hepatosplenomegaly.  No joint swelling is present.  Further evaluation of this patient would most likely reveal a deficiency in which of the following?

Quizplus · Accepted Answer

11ec25c8_d694_b73b_bc81_bb4bb5dfb3c9_MD0003_00 This patient's bruising, lymphadenopathy, and hepatosplenomegaly are most likely due to acute lymphoblastic leukemia (ALL). ALL is the most common childhood cancer, with peak incidence in boys age 2-5. About half of patients with ALL have bruising, petechiae, and mucosal bleeding (eg, oozing from the gums) as a result of cancer cells infiltrating the bone marrow and impairing platelet production. Bone marrow failure leads to pallor and fatigue (from anemia) and recurrent infections (from neutropenia). petechiae In addition, the spread of leukemic cells out of the bone marrow can cause the liver, spleen, and lymph nodes to enlarge. In contrast to infectious causes of lymphadenopathy, malignant nodes are typically firm and nontender, as seen in this child. Bone marrow biopsy is diagnostic. (Choice A) Connective tissue disorders (eg, Ehlers-Danlos syndrome) may present with fragile, easily bruised skin due to impaired collagen synthesis; however, lymphadenopathy and hepatosplenomegaly would not be expected. (Choice B) Hemophilia A (factor VIII deficiency) typically presents with prolonged bleeding after minor trauma (eg, hemarthrosis). Although this patient has a family history of hemophilia, the disease is X-linked recessive and inherited from maternal chromosomes (not the paternal uncle). In addition, this patient had no bleeding complications after a tonsillectomy. (Choice C) Factor XIII deficiency is a rare disorder that typically presents in the neonatal period with bleeding from the umbilical stump. It is unlikely in this patient who had no postoperative bleeding. (Choice E) Factor VII requires vitamin K-dependent gamma-carboxylation to be active in the clotting pathway. In pediatrics, vitamin K deficiency is typically seen in chronic disorders of fat malabsorption (eg, cystic fibrosis, biliary atresia) and is unlikely in this previously healthy child with no gastrointestinal symptoms. (Choice F) Von Willebrand factor is a protein that allows platelet adhesion. Decreased production, as seen in von Willebrand disease, typically presents with minor bruising and bleeding despite a normal platelet count. This condition would not explain this patient's lymphadenopathy and hepatosplenomegaly. Educational objective: Acute lymphoblastic leukemia often presents with bruising, petechiae, and bleeding due to impaired platelet production in the bone marrow. Other common findings are nontender lymphadenopathy and hepatosplenomegaly. References: Leukemia: an overview for primary care. (http://www.ncbi.nlm.nih.gov/pubmed/24784336)

A 4-Year-Old Boy Is Brought to the Office by His