Page 136 - Essential Haematology

122 / Chapter 8 White cells: Granulocytes and monocytes

multisystem disease who do not respond to

Table 8.7 Classifi cation of the histiocytic and
dendritic cell disorders. chemotherapy.
Benign Haemophagocytic l ymphohistiocytosis
Dendritic cell - related ( h aemophagocytic s yndrome)
Langerhans ’ cell histiocytosis
This is a rare, recessively inherited or more fre-

Solitary dendritic cell histiocytoma
quently acquired disease, usually precipitated by a
Histiocyte - related viral (especially Epstein – Barr or herpes viruses),
Haemophagocytic lymphohistiocytosis bacterial or fungal infection or occuring in associa-
primary (familial) tion with tumours. Often the patient is immuno-
secondary – infection, drug, tumour compromised. Patients present with fever and
Sinus histiocytosis with massive pancytopenia, often with splenomegaly and liver
lymphadenopathy (Rosai – Dorfman syndrome)

dysfunction. There are increased numbers of histio-
Malignant cytes in the bone marrow which ingest red cells,
Dendritic and histiocytic sarcomas (localized or white cells and platelets (Fig. 8.12 ). Clinical features
disseminated) are fever, pancytopenia and multiorgan dysfunction

AML, monocytic and myelomonocytic (see p. often with lymphadenopathy, hepatic and splenic

179) enlargement, coagulopathy and CNS signs.
Chronic myelomonocytic leukaemia (see p. 221) Treatment is of the underlying infection, if known,

with support care. T - cell activation is implicated in
AML, acute myeloid leukaemia. the aetiology. Chemotherapy with etoposide, corti-
costeroids, ciclosporin or rituximab (anti - CD20)
may be tried. The condition is often fatal.

2 A lymphocyte - derived subset. The primary role

of dendritic cells is antigen presentation to T and
Sinus h istiocytosis with m assive
B lymphocytes (see p. 133) .
l ymphadenopathy
Th is is also known as the Rosai – Dorfman syn-
Langerhans ’ c ell h istiocytes

drome. There is painless, chronic cervical lymphad-
Langerhans ’ cell histiocytosis (LCH) includes dis- enopathy. There may be fever and weight loss. Th e

eases previously called histiocytosis X, Letterer – Siwe histology is typical and the condition subsides over
disease Hand – Sch ü ller – Christian disease and eosi- months or years.
,
nophilic granuloma . The disease may be single organ

or multisystem. There is a clonal proliferation of Lysosomal s torage d iseases

CD1a - positive cells. The multisystem disease aff ects

children in the first 3 years of life with hepato- Gaucher ’ s, Tay – Sachs and Niemann – Pick diseases

splenomegaly, lymphadenopathy and eczematous result from hereditary deficiency of enzymes
skin symptoms. Localized lesions may occur espe- required for glycolipid breakdown.
cially in the skull, ribs and long bones, the posterior
pituitary causing diabetes insipidus, the central
Gaucher ’ s d isease
nervous system, gastrointestinal tract and lungs.
’
The lesions include Langerhans ’ cells (characterized Gaucher s disease is an uncommon autosomal reces-

by the presence of tennis racquet - shaped Birbeck sive disorder characterized by an accumulation of
granules in electron - microscopy sections), eosi- glucosylceramide in the lysosomes of reticuloen-

nophils, lymphocytes, neutrophils and macro- dothelial cells as a result of deficiency of glucocere-

phages. The prognosis is better for localized disease brosidase (Fig. 8.13 . Three types occur: a chronic
but there is a 66% mortality in young children with adult type (type I); an acute infantile neuronopathic