Langerhans cell histiocytosis Flashcards
(11 cards)
What is Langerhans cell histiocytosis characterized by?
Overproduction of Langerhans cells
Langerhans cells are dendritic cells of the skin that function as antigen-presenting cells.
What is the primary function of dendritic cells?
Strict antigen-presenting cells (APCs)
Dendritic cells phagocytose antigens and present them to CD4+ T cells.
Which other cells are also considered antigen-presenting cells?
Macrophages and B-cells
Macrophages and B-cells are also APCs, but they are not dendritic cells because
they have additional functions – i.e., macrophages destroy antigens; B cells mature into plasma cells and
produce antibodies.
Where do Langerhans cells notably over-proliferate in Langerhans cell histiocytosis?
In bone
This over-proliferation causes lytic lesions, such as those found in the skull.
What are Birbeck granules?
Tennis racquet- or rod-shaped inclusions within Langerhans cells
They can be visualized on electron microscopy.
How can Langerhans cell histiocytosis (LCH) present in children?
As a lytic lesion of the skull
Diagnosis may involve imaging showing Langerhans cells with specific characteristics.
Describe the appearance of Langerhans cells in LCH.
Large, irregularly shaped cells with copious eosinophilic cytoplasm and horseshoe- or kidney-shaped nuclei
These characteristics help in the diagnosis of LCH.
Tennis racquet-shaped Birbeck granules in Langerhans cell histiocytosis
Rod-shaped Birbeck granules in Langerhans cell histiocytosis
Langerhans cells in LCH
appear as large, irregularly shaped cells with copious eosinophilic cytoplasm and characteristic
horseshoe- or kidney-shaped nuclei
Along with lytic bone lesions, Langerhans cell histocytosis can present with
Erythematous rash
CNS involvement (ie pituitary involvement causing central diabetes insipidus (polyuria, polydipsia, hypernatremia))
