Differential Diagnosis
The patient's symptoms and laboratory results suggest a complex condition. Here's a categorized differential diagnosis:
Single most likely diagnosis
- A. Acute lymphoblastic leukemia (ALL): The patient's symptoms, such as persistent leg pain, refusal to walk, and a mild, nonproductive cough, are consistent with ALL. The laboratory results, including a low hemoglobin level (8 g/dL), thrombocytopenia (30,000/mm3), and leukopenia (3,000/mm3), also support this diagnosis. The hepatomegaly (liver palpated 3 cm below the costal margin) is another common finding in ALL.
Other Likely diagnoses
- E. Nonaccidental trauma: The presence of scattered bruises across the chest and back, along with the patient's leg pain and refusal to walk, raises concerns about nonaccidental trauma. However, the laboratory results and other symptoms are more suggestive of a systemic illness like ALL.
- B. Aplastic anemia: Although the patient's laboratory results show pancytopenia (low hemoglobin, platelets, and leukocytes), aplastic anemia is less likely given the presence of hepatomegaly and the patient's symptoms.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Infection (e.g., osteomyelitis or septic arthritis): The patient's fever (38.3 C) and leg pain could be indicative of an infection. Although the laboratory results suggest a hematologic disorder, it's essential to consider and rule out infections, as they can be life-threatening if left untreated.
- Child abuse with a concomitant medical condition: It's crucial to consider the possibility of child abuse, especially given the patient's bruises and the fact that the mother's boyfriend reported the incident. A thorough investigation and examination are necessary to determine the cause of the patient's injuries.
Rare diagnoses
- C. Immune thrombocytopenia: Although the patient has thrombocytopenia, immune thrombocytopenia is less likely given the presence of anemia, leukopenia, and hepatomegaly.
- D. Juvenile idiopathic arthritis: This condition can cause leg pain and refusal to walk, but it is less likely given the patient's laboratory results and other symptoms, which suggest a hematologic disorder.