Langerhans Cell Histiocytosis

Question 1

Langerhan cells

Answer 1

Derived from bone marrow monocytes
DCs in skin
present Ag to naive T-cells

Question 2

Langerhan cell histiocytosis

Answer 2

Neoplastic prolif of langerhan cells
Birbeck (tennis racket) granules
CD1a+, S100+, CD207+ (langerin)

Question 3

Subtypes of LCH

Answer 3

Letterer-Siwe dz
Eosinophilic granuloma
Hand Schuler-Christian dz

Question 4

Letterer-Siwe dz

Answer 4

Multifocal multisystem
Malignant prolif of langerhan cells
Skin rash and cystic skeletal defects in infants
Rapidly fatal

Question 5

Eosinophilic granuloma

Answer 5

Unifocal lesions
Benign prolif of Langerhan cells in bone
Cells w/ folded or grooved nuclei and moderately abundant Pale cytoplasm w/ a few eosinophils
Mixed inflammatory cells

Question 6

Hand Schuller-Christian dz

Answer 6

Multifocal unisystem
Malignant prolif of Langerhan cells
Scalp rash, lytic skull lesions, diabetes insipidus, Exophthalmos in child