Langerhans cell histiocytosis, LCH, histiocytosis X

Definition

A neoplasm of Langerhans cells expressing CD1a, S-100 and containing Birbeck granules.

Equivalent normal cell

Langerhans cells are found in the epidermis, cervix, vagina, stomach and oesophagus. They have a dendritic morphology and contain Birbeck granules, show low levels of lysosomal enzymes and play a key role in antigen presentation. They are CD1a+/S-100+/CD21-/CD35-/CD86-. Veiled cells are Langerhans cells or interstitial dendritic cells which have migrated to local lymphoid tissue following antigen capture; they lack Birbeck granules and complex interdigitating cell junctions1.

Epidemiology

The incidence is 5 per million. This is predominantly a disease of childhood, with a male predominance. There is an association of systemic LCH with acute lymphoblastic leukaemia, lymphoma (FL1), germ cell tumours1. and with solvent exposure. LCH of the lung is an adult condition, strongly associated with tobacco smoking and may represent a separate reactive entity.

Clinical features

Histopathology

Langerhans cells predominate, with grooved nuclei. There are variable numbers of eosinophils, mononuclear and multinucleate histiocytes, neutrophils and small lymphocytes. There may be eosinophil microabscesses. Involvement of lymph nodes is commonly sinusoidal1.

Immunohistochemistry; see the immunohistochemical differentiation of histiocytic and dendritic cell neoplasms

both should be positive

 

S-100

positive0; 17/171

 

CD1a

positive0; 17/171

fascin

34/342

vimentin

usually positive0

HLA-DR

usually positive0

peanut agglutinin lectin

usually positive0

placental alkaline phosphatase

usually positive0

CD45

variably weakly positive0, 10/151

CD68

variably weakly positive0, 16/171

lysozyme

variably weakly positive0, 15/161

CD4

may be positive0

myeloid markers: should be negative0

myeloperoxidase

0/151

CD34

0/121

FDC-markers

CD21

almost always negative0, 0/171

CD35

almost always negative0, 1/161

CNA.42

5/171

T-lineage markers: should be negative0

CD3

0/161

B-lineage markers: should be negative0

CD20

0/141

CD79a

0/111

CD35

almost always negative0, 0/161

others

CD15

usually negative0

CD30

0/141

 
 

Ultrastructure

Birbeck granules are present in most cases. Complex interdigitating cellular processes are absent1. Desmosomes and lysosomes may be seen1.

Differential diagnosis

Prognosis

About one third of cases prove fatal1.

References

0World Health Organization Classification of Tumours, Tumours of the haematopoietic and lymphoid tissues, IARC Press 2001.

1Pileri, S.A., Grogan, T.M., Harris, N.L., et al. Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases. Histopathology 2002;41:1-29.

2 Pinkus GS, Lones MA, Matsumura F, et al. Langerhans cell histiocytosis immunohistochemical expression of fascin, a dendritic cell marker. Am J Clin Pathol 2002; 118:335-43

 

This page last revised 16.7.2005.

©SMUHT/PW Bishop