A 17-year-old patient is referred to you for a platelet count of 1,200,000/mm3. On history, she notes that she often has numbness and tingling in her hands and feet and has frequent epistaxis. She is otherwise well-appearing and has no recent infections. On her exam, you note splenomegaly. What do you expect to see on further evaluation?

Correct Answer: D

Rationale: The correct answer is D: Low von Willebrand factor activity. A platelet count of 1,200,000/mm3 suggests thrombocytosis, which can be seen in conditions like essential thrombocythemia. This condition is associated with low von Willebrand factor activity, leading to increased bleeding tendency despite high platelet counts. Numbness, tingling, epistaxis, and splenomegaly are common features of essential thrombocythemia. Elevated C-reactive protein is not typically associated with this condition. Low ferritin is more indicative of iron deficiency anemia, not thrombocytosis. A hypocellular bone marrow is not expected in essential thrombocythemia, as it is characterized by increased platelet production.

Correct Answer: A

Rationale: The correct answer is A: Safe, timely, effective, efficient, equitable, and person-centered. This aligns with the six dimensions of quality care outlined by the Institute of Medicine. Safety ensures patient well-being, timeliness reduces delays, effectiveness means providing evidence-based care, efficiency minimizes waste, equity ensures fair access, and person-centered care considers individual preferences. Choice B is incorrect because transparency is not included in the Institute of Medicine's six dimensions. Choice C is incorrect as "low-cost" is not a recognized dimension of quality care. Choice D is incorrect because "cutting-edge" is not part of the established dimensions of quality care.

Correct Answer: C

Rationale: The correct answer is C: Chronic myeloid leukemia (CML). This is a likely diagnosis due to the presence of fatigue, weight loss, night sweats, splenomegaly, anemia, thrombocytosis, and leukocytosis with an elevated white blood cell count. CML is characterized by the Philadelphia chromosome, resulting in the BCR-ABL fusion gene. This gene leads to uncontrolled proliferation of myeloid cells, causing the symptoms seen in this patient. Leukemoid reaction (A) is a reactive increase in white blood cells, usually in response to an infection. Acute lymphoblastic leukemia (B) typically presents with symptoms in children but is more commonly associated with lymphoblasts in the peripheral blood. JMML (D) is a rare myelodysplastic disorder in children characterized by monocytosis and a specific genetic mutation.

Correct Answer: D

Rationale: The correct next step is D: Obtain labs, including a CBC with platelet count and fibrinogen. This is the most appropriate action because the infant presents with an indurated and purpuric lesion with petechiae, suggesting a possible coagulation disorder. Labs can help assess for any underlying hematologic abnormalities. Choice A is incorrect because it is important to investigate further given the concerning presentation. Choice B is not the best next step as an ultrasound would not provide information on the hematologic status. Choice C is also not the best option as an MRI is not typically used to assess coagulation disorders.

Correct Answer: D

Rationale: The correct answer is D: Kruskal-Wallis test. Since the LOS data is not normally distributed, parametric tests like Student's t test and ANOVA are not appropriate. The Kruskal-Wallis test is a non-parametric test used to compare three or more independent groups when the data is not normally distributed. It ranks the LOS values across the three central line types and tests whether there are differences in medians. The Wilcoxon-Mann-Whitney test (choice C) is used for comparing two independent groups, not three. Therefore, it is not the appropriate test in this scenario.