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oncology

Langerhans Cell Histiocytosis (LCH)

intermediate
6 min
28 marks
6 questions
Clinical Scenario
A 6-year-old boy presents with a 4-week history of a painful lump on his head. His mother noticed swelling over the right parietal area. He is otherwise well with no fever, weight loss, or other symptoms. On examination, there is a tender, soft swelling over the right parietal skull with normal overlying skin. Laboratory tests show normal inflammatory markers. Skull X-ray reveals a well-defined "punched-out" lytic lesion.
Lateral skull radiograph demonstrating a solitary 'punched-out' lytic lesion in the parietal bone characteristic of Langerhans cell histiocytosis (eosinophilic granuloma). The lesion has sharp, well-defined margins with a 'beveled edge' (inner table destroyed more than outer). There is no sclerotic rim or periosteal reaction. This appearance in a child is virtually pathognomonic for LCH.
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Lateral skull radiograph demonstrating a solitary 'punched-out' lytic lesion in the parietal bone characteristic of Langerhans cell histiocytosis (eosinophilic granuloma). The lesion has sharp, well-defined margins with a 'beveled edge' (inner table destroyed more than outer). There is no sclerotic rim or periosteal reaction. This appearance in a child is virtually pathognomonic for LCH.

Image source: Open Access medical literature (NIH/PubMed Central) • CC-BY License

Questions

Question 1 (4 marks)

Describe the clinical and radiographic features of Langerhans cell histiocytosis.

Question 2 (5 marks)

What is the classification and spectrum of disease?

Question 3 (6 marks)

Describe the diagnostic workup and histological features.

Question 4 (5 marks)

What are the treatment options?

Question 5 (4 marks)

What are the differential diagnoses?

Question 6 (4 marks)

Discuss prognosis and outcomes.

Exam Day Cheat Sheet

Must Mention

  • •Peak age 5-10 years
  • •Punched-out lytic, beveled edge (skull)
  • •CD1a+, S100+, Birbeck granules
  • •Spectrum: single bone → multisystem
  • •Most single lesions resolve or respond to local treatment
  • •Vertebra plana often reconstitutes

Common Pitfalls

  • •Wrong age group
  • •Missing IHC markers
  • •Unnecessary radiation
  • •Wrong prognosis
  • •Missing DI risk
  • •Confusing with Ewing/myeloma