An 11-year-old girl with systemic juvenile rheumatoid arthritis appears with fever, lymphadenopathy, and hepatosplenomegaly. The blood test reveals anemia, leukopenia, and thrombocytopenia. This is most likely due to:

Correct Answer: B

Rationale: Macrophage activation syndrome is a severe complication of systemic JIA, marked by fever, organomegaly, and cytopenias from hemophagocytosis (EULAR criteria). Viral syndrome lacks specificity, hemolytic anemia doesn’t fit all findings, spleen failure is unclear, and DIC requires coagulopathy evidence.

Correct Answer: B

Rationale: Turner syndrome with Y-chromosome material raises gonadoblastoma risk due to dysgenetic gonads (NORD). Other conditions (A, C-E) lack this link.

Correct Answer: D

Rationale: Liver enzymes aren’t routine for initial metabolic acidosis workup; A-C, E assess cause and severity (AAP).

Correct Answer: C

Rationale: Abdominal circumference and femoral length together are most accurate at term (ACOG). A-D are less reliable late.

Correct Answer: A

Rationale: Distal ileum is the most common NEC site in preterms, per AAP. A-D are less frequent.