6.9 Langerhans Cell Histiocytosis

Question 1

What are Langerhans cells?

Answer 1

Specialized dendritic cells found in the skin and are derived from bone marrow monocytes

Question 2

Langerhans Cell Histiocytosis

Answer 2

Neoplastic proliferation of Langerhans cells

Question 3

What are the characteristic granules seen with Langerhans cell histiocytosis?

Answer 3

Birbeck Granules - shaped like tennis rackets

Question 4

What immunohistochemistry markers are positive with Langerhans cell histiocytosis?

Answer 4

• CD1a

- S100

Question 5

Letterer-Site Disease

Answer 5

Malignant proliferation of Langerhans cells that presents classically as a skin rash

Question 6

Eosinophilic Granuloma

Answer 6

Benign proliferation of Langerhans cells in the bone that classically presents as a pathological fracture in an adolescent

Question 7

Hand-Schuller-Christian Disease

Answer 7

Malignant proliferation of Langerhans cells that classically presents with a scalp rash, lytic skull lesions and diabetes insipidus in a child