Langerhans cell histiocytosis

Langerhans cell histiocytosis (PLCH) (also known as Langerhans cell granulomatosis, eosinophilic granuloma, and histiocytosis X)

Although monocytes-macrophages were originally thought to be the major antigen-presenting cells (APCs) of the immune system, it is now clear that dendritic/Langerhans cells are the most potent and effective APCs in the body.

Dendritic/Langerhans Cells Dendritic/Langerhans cells are bone marrow-derived APCs that are distinct from monocytes-macrophages and are derived from both lymphoid and myeloid lineages.

Dendritic cells are referred to as Langerhans cells when they are present in the skin and beneath the mucosal surface. They comprise the dendritic cells of the blood and the spleen and the veil cells of afferent lymphatics, and they form part of the interdigitating cell network of lymphoid organs.

Large granular lymphocytes (LGLs) account for approximately 5 to 10% of peripheral blood lymphocytes. LGLs are nonadherent, nonphagocytic cells with large azurophilic cytoplasmic granules.

Amyloidosis
Connective tissue naevi
Dermatofibroma
Dermatofibrosarcoma protuberans
Ehler's Danlos syndrome
Elastosis perforans serpiginosa
Keloids & hypertrophic scars
Lipodystrophy
Lipoma
Mastocytoma
Neurofibroma
Pseudoxanthoma elasticum
Reactive perforating collagenosis
Striae (stretch marks)
Eosinophilic fasciitis
Erythema multiforme
Histiocytoses
Jessner's lymphocytic infiltrate
Langerhans cell histiocytosis
Lymphocytoma cutis
Lymphomatoid papulosis
Mastocytosis
Morphoea
Non-Langerhans cell histiocytosis
Panniculitis
Reticulohistiocytosis
Sweet's disease
Systemic sclerosis
Atypical mycobacterial infection
Granuloma faciale
Granuloma annulare
Cutaneous tuberculosis
Leprosy
Pyogenic granuloma
Sarcoidosis