Yet another limp

A 5 year old boy is brought in by his parents, as he has been limping on his left leg for 4 days. Further questioning reveals that he was generally unwell during the preceding 3 weeks.

There is no history of trauma and his medical history is unremarkable.

X-rays of the left hip joint and knee are obtained, but no abnormalities are apparent.

Select Relevant Investigations
Full Blood Count

Performed

WBC 4,500/mm3 (5,000 - 14,500)
Neu: 30%; Lym: 65%
Hb: 9.2 g/dL (11.5 - 14.5)
Plt: 170,000/mm3 (250,000 - 550,000)
Blood film: A normochromic normocytic anemia is seen; a few atypical cells are also noted.
ESR & CRP

Performed

ESR: 62 mm/1h (< 5)
CRP: 24 mg/dL (< 6)
Bone Marrow Biopsy

Performed

The bone marrow biopsy shows a hypercellular bone marrow with widespread infiltration of hematopoietic tissue by lymphoblasts. Normal hematopoietic elements are markedly reduced.
Lumbar Puncture

Performed

Appearance: Clear
WBC: No polymorphs
RBC: nil
Gram stain: negative
Glucose: 90 mg/dl (normal)
Protein: 25 mg/dl (normal)

Select Relevant Management
Chemotherapy
Cranial irradiation
Radiotherapy L/hip joint
NSAIDs