Page 34 of 34
PE26.1-17 | Hemato-Oncology — PBL Case
CLINICAL SETTING
You are a final-year MBBS student posted in the Paediatrics ward of a tertiary care teaching hospital in Pondicherry. It is a busy Monday morning. The registrar asks your group to review three children admitted overnight — each with pallor or bleeding. By the end of the session, you will need to have reasoned through their diagnoses, investigation plans, management strategies, and family counselling.
Trigger 1: Trigger 1 — Ramu's Swollen Knee
Ramu, a 5-year-old boy, was brought in by his father at 11 pm after the boy fell while playing and developed a rapidly swelling, painful right knee. The swelling appeared within 30 minutes. On examination: the child is in moderate distress, right knee is warm, swollen, and tender, with restricted range of motion. He is pale. His mother mentions that Ramu had prolonged bleeding after circumcision at age 1 and that her two brothers both had 'blood problems' requiring hospital visits frequently. Ramu has never had surgery. Vital signs: Pulse 108, BP 90/60, temperature 37.2°C. Investigations ordered by the casualty doctor: - Hb: 9.2 g/dL - WBC: 8,400/µL, differential normal - Platelets: 1,85,000/µL - Bleeding time: 3 minutes (normal) - PT: 13 seconds (control 13) — normal - aPTT: 68 seconds (control 32) — PROLONGED
DISCUSSION POINTS
- What is the differential diagnosis for a child with haemarthrosis and prolonged aPTT but normal PT and platelets?
- What does the family history pattern (maternal uncles affected, male child affected) suggest about the inheritance? Which single investigation would you order next to confirm the diagnosis?
- What is the immediate management for this child's knee bleed? What medications must be strictly avoided, and why?
- Calculate the Factor VIII dose needed to raise his level to 50% if he weighs 18 kg.
Click to reveal Trigger 2: Trigger 2 — Priya's Spots and Pallor (discuss previous trigger first!)
Trigger 2: Trigger 2 — Priya's Spots and Pallor
In the next bed is Priya, a 4-year-old girl, brought by her mother who noticed 'red spots all over the legs and stomach' since yesterday. The child had a viral fever (no specific diagnosis) 3 weeks ago that resolved in 5 days. She is currently afebrile and well-looking. On examination: multiple petechiae over lower limbs and abdomen, no ecchymoses, no lymphadenopathy, no hepatosplenomegaly, no pallor of mucous membranes. Priya is eating well and playful. CBC results: - Hb: 11.8 g/dL (normal) - WBC: 7,200/µL, normal differential, no blasts - Platelets: 9,000/µL — severely reduced - Peripheral smear: only reduced platelets noted; no blast cells, no morphological RBC abnormality - Coagulation studies: PT, aPTT — both normal
DISCUSSION POINTS
- What is the most likely diagnosis, and what key features in the history and examination help you distinguish this from acute leukaemia and aplastic anaemia?
- At what platelet count and in what clinical scenarios would you initiate active treatment (IVIG or steroids) rather than observe?
- The mother is very anxious and asks 'Is this cancer?' — how would you counsel her? What activity modifications should you recommend?
- What are the referral criteria for this condition, and when would you refer Priya to a paediatric haematologist?
Click to reveal Trigger 3: Trigger 3 — Arjun's Pallor and Weight Loss (discuss previous trigger first!)
Trigger 3: Trigger 3 — Arjun's Pallor and Weight Loss
The third child is Arjun, a 3-year-old boy from a rural area of Tamil Nadu. He has had progressive pallor, poor appetite, and weight loss for 6 weeks. His parents noticed his belly seemed larger. He has had two episodes of fever in the last month. On examination: marked pallor (conjunctival and palmar), no jaundice, generalised lymphadenopathy (bilateral cervical, axillary, inguinal — largest node 2 cm, non-tender, firm), hepatomegaly (4 cm below costal margin), splenomegaly (6 cm below costal margin). No petechiae. CBC: - Hb: 6.8 g/dL - WBC: 42,000/µL with 75% blasts on smear - Platelets: 22,000/µL - Peripheral smear: lymphoblasts predominant, few normal lymphocytes Flow cytometry is pending. Bone marrow aspirate shows 82% lymphoblasts. Faculty informs the group: the family is from a small village; the father is a daily wage labourer; the family has limited understanding of the diagnosis.
DISCUSSION POINTS
- State the diagnosis. What are the high-risk features in Arjun's presentation that predict increased tumour lysis syndrome (TLS) risk?
- Describe the monitoring protocol and prophylaxis for TLS in the first 72 hours of chemotherapy initiation.
- How would you communicate the diagnosis of ALL to Arjun's parents? What government/national health programme resources are available for leukaemia care in India?
- What are the absolute contraindications for intramuscular injections in Arjun during induction? What analgesic alternatives are safe?
Click to reveal Trigger 4: Trigger 4 — Connecting the Dots: Blood Tests and Beyond (discuss previous trigger first!)
Trigger 4: Trigger 4 — Connecting the Dots: Blood Tests and Beyond
The next morning, additional results arrive: - Ramu: Factor VIII activity 1.2% (severe haemophilia A confirmed) - Priya: bone marrow aspirate (done to exclude ALL) — shows NORMAL cellularity with increased megakaryocytes and erythroid precursors, confirming immune thrombocytopenic purpura. After 24 hours of observation, she develops gum bleeding. - Arjun: lactate dehydrogenase 2,840 U/L (markedly elevated), uric acid 11.2 mg/dL, potassium 5.9 mEq/L, phosphate 7.2 mg/dL, calcium 7.1 mg/dL — clinical tumour lysis syndrome present before chemotherapy starts. The ward paediatric haematologist reviews all three children and asks your group to present management summaries for each child to the family.
DISCUSSION POINTS
- For Ramu: what is the long-term management plan for severe haemophilia A including prophylaxis regimen, career counselling, and genetic counselling for his mother?
- For Priya: she now has mucosal bleeding with platelet count 9,000/µL. Which treatment do you initiate — IVIG or prednisolone? Justify with doses, timeline for response, and what you would do if the first-line treatment fails within 48 hours.
- For Arjun: clinical TLS is already established. Outline the emergency management: fluid, electrolyte correction, and choice between allopurinol and rasburicase.
- The haematologist asks your group: 'Which of these three children would you refer to a specialised centre, and on what criteria?' Discuss referral criteria for each using national guidelines.
Group Task Assignments
Group 1: Collaborative Task
Group 2: Collaborative Task
Group 3: Collaborative Task
Group 4: Collaborative Task
Learning Issues
Research these questions and bring your findings to the discussion.
- [PE26.1] What is the approach to classifying anaemia by MCV, and how does the Mentzer index help differentiate IDA from thalassaemia trait at the bedside?
- [PE26.4] What are the distinct mechanisms of haemolysis in thalassaemia major, sickle cell disease, G6PD deficiency, and hereditary spherocytosis, and how does the peripheral smear help distinguish them?
- [PE26.6] What are the diagnostic criteria and management thresholds for childhood ITP, and when is watchful waiting appropriate versus active treatment?
- [PE26.7] How does the X-linked inheritance of haemophilia A and B manifest in family pedigrees, and what is the correct approach to factor replacement therapy for haemarthrosis?
- [PE26.8] What pathophysiological events cause tumour lysis syndrome in ALL, and how should TLS be monitored and prevented during induction chemotherapy?
- [PE26.11] How do you interpret a CBC and LFT in the context of haematological disease, with particular attention to age-specific Hb cut-offs and coagulation test patterns?
- [PE26.12] What are the key peripheral smear findings that distinguish IDA, thalassaemia, sickle cell disease, G6PD deficiency, hereditary spherocytosis, and ALL?
- [PE26.15] What are the referral criteria for haematological conditions in children — specifically for severe haemophilia, chronic/refractory ITP, thalassaemia major, and ALL — to specialised paediatric haematology centres?
- [PE26.16] How should a paediatrician counsel families about prevention and treatment of nutritional anaemia, including dietary advice, national programme resources, and follow-up monitoring?
- [PE26.17] What are the indications for splenectomy in paediatric haematological conditions, and what pre- and post-operative precautions are mandatory to reduce post-splenectomy infection risk?