Clinical scenario
A 17-year-old male is brought to the emergency department due to rapidly progressive bilateral facial palsy over the past two days — complains of severe fatigue and bone pain and easy bruising on his arms and legs — no fever
Clinical examination
Examination: marked pallor — widespread petechiae — cervical and axillary lymphadenopathy — bilateral facial palsy grade IV to V by House-Brackmann classification — retinal hemorrhage on fundoscopy
Labs & imaging
No initial investigations yet — the most important initial test must be selected
What is the most important initial investigation that should be performed immediately?
Academic Discussion: The clinical features of fatigue and pallor and bone pain and easy bruising and lymphadenopathy with bilateral facial palsy strongly raise suspicion for acute leukemia — complete blood count with peripheral smear is a rapid and decisive test that can detect thrombocytopenia and anemia and the presence of blast cells | Differential Diagnosis: CT head does not detect leukemia — lumbar puncture is dangerous in the absence of prior imaging and thrombocytopenia — lymph node biopsy is slower and lower priority at this stage — ANA does not explain this presentation | Distinguishing Features: The complete symptom complex with bilateral facial palsy strongly suggests leukemia — bilateral facial palsy is rare and mandates serious investigation for a systemic cause | Work-up Logic: Immediate CBC with smear — bone marrow examination when suspicion is confirmed — CT imaging to exclude hemorrhage if neurological deterioration occurs | Results Interpretation: Blast cells on the smear confirm the diagnosis | Initial Management: Immediate referral to hematology-oncology — blood transfusion if hemoglobin is critically low | When to Observe: No role for observation | When to Start Medical Therapy: Chemotherapy after diagnosis is confirmed | When to Admit: Immediately | When it is an Emergency: This is an emergency | When to Escalate Airway / ICU: When consciousness deteriorates or severe hemorrhage occurs | When Surgery is Indicated: No surgical role in the initial phase | Complications: Hemorrhage — infection — organ failure | Red Flags: Retinal hemorrhage — spontaneous bruising — sudden bilateral palsy | Clinical Pitfalls: Assuming bilateral Bell palsy without investigating for a systemic cause | Follow-up and Referral: Immediate referral to hematology-oncology | Consultant Pearl: Sudden bilateral facial palsy in a young person with systemic symptoms always mandates urgent investigation for acute leukemia as the highest priority