Patient: 7-year-old boy Presentation: Localised skull pain and tender swelling over the right parietal region for 3 weeks, worse at night, mild irritability Relevant history: Previously well, no weight loss, no polyuria/polydipsia, normal development, no family history of malignancy Examination findings:
| Test | Result | Normal Range | Interpretation |
|---|---|---|---|
| Haemoglobin | 125 g/L | 115-145 | Normal |
| WCC | 8.2 x 10⁹/L | 5-13 | Normal |
| Platelets | 280 x 10⁹/L | 150-400 | Normal |
| ESR | 25 mm/hr | 0-10 | Mildly elevated |
| CRP | 8 mg/L | <5 | Mildly elevated |
| LDH | 180 U/L | 120-300 | Normal |
| ALP | 220 U/L | 150-400 | Normal (child) |
| Albumin | 42 g/L | 35-50 | Normal |
| LFTs | Normal | - | No liver involvement |
| Urine osmolality | 650 mOsm/kg | 500-800 | Normal (no DI) |
Image 1: Skull X-ray (AP and Lateral)
Radiological features:
Image 2: CT Head with Bone Windows
CT findings:
Image 3: Skeletal Survey
Findings:
What is the likely diagnosis and describe the spectrum of this disease?
What investigations would you perform to stage this patient?
What histological findings would confirm the diagnosis?
How would you manage this patient with unifocal skull LCH?
What if this patient had vertebral involvement with vertebra plana?
What features would indicate multisystem disease and how would management change?
This pattern suggests Eosinophilic Granuloma (Unifocal LCH):
Distinguish from Other Lesions:
| Feature | LCH | Osteomyelitis | Ewing Sarcoma |
|---|---|---|---|
| Age | 5-15 years | Any | 10-20 years |
| Margin | Punched-out | Ill-defined | Permeative |
| Periosteal reaction | Minimal | Aggressive | Onion-skin |
| Soft tissue mass | Small | Abscess | Large |
| Systemic symptoms | Rare | Fever, malaise | B symptoms |
Q: "Why does bone scan miss LCH lesions?"
LCH lesions are often "cold" on bone scan because:
Therefore, skeletal survey (plain X-rays) is the preferred staging modality.
Q: "What is the role of chemotherapy in LCH?"
| Indication | Agents |
|---|---|
| Not indicated | Unifocal bone lesion |
| Indicated | Multifocal bone disease |
| Indicated | Any multisystem involvement |
| First-line | Vinblastine + prednisolone x 12 months |
| Salvage | Cladribine, cytarabine |
Q: "What are the late effects of LCH?"
| Late Effect | Incidence | Management |
|---|---|---|
| Diabetes insipidus | 15-25% | DDAVP lifelong |
| Growth hormone deficiency | 10% | GH replacement |
| Orthopaedic sequelae | 20% | Usually mild |
| Hearing loss | 10-15% | If temporal bone involved |
| Neurodegenerative disease | 1-4% | Cerebellar, rare |
Q: "Can LCH recur?"
| Disease Type | Recurrence Rate | Notes |
|---|---|---|
| Unifocal | 10-15% | Usually another bone lesion |
| Multifocal | 30-40% | May need prolonged therapy |
| Multisystem | 50-60% | May need salvage chemotherapy |
Recurrence is most common within 2 years of diagnosis. Follow-up should continue for at least 5 years.