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.
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