Pediatric Radiology > Musculoskeletal > Aggressive Lesions > Langerhans Cell Histiocytosis


Langerhans Cell Histiocytosis

Langerhans Cell Histiocytosis (LCH), previously known as histiocytosis X, is an idiopathic disease characterized by abnormal proliferation of Langerhans cells. The disease can exist along a spectrum from localized to systemic manifestations. The disease is more common in males > females (2:1), and more prevalent amongst the caucasian population.

Radiographic findings are highly variable; bony lesions may be sclerotic or lucent, have a sclerotic or poorly-defined border, and be permeative or geographic in appearance. The most common sites with radiographic findings are: skull > ribs > femur > pelvis > spine > mandible.

Classification is controversial but the 3 main clinical subtypes of LCH are:

Unifocal, previously known as Eosinophilic Granuloma - most common form with best prognosis; disease isolated to bone or lung; usually presents between 5 and 15 years of age

  • punched-out lytic skull lesions
  • vertebra plana (vertebral destruction with vertebral collapse)
  • lytic lesions in other bones (e.g. mandible - destruction of alveolar bone causes the "floating teeth" appearance)

Multisystem, previously known as Letterer-Sewe disease - acute, diffuse, and often fatal; worst prognosis; usually presents before age 2

  • rash
  • hepatosplenomegaly
  • lymphadenopathy
  • pulmonary involvement
  • marrow failure

Multifocal, previously known as Hand-Schuller-Christian disease - chronic and diffuse with high morbidity; fatal in about 15% of patients; usually presents before age 5

  • predilection for skull defects
  • exopthalmos (from mass effect of orbital bone disease)
  • diabetes insipidus (from basilar skull disease or infiltration of posterior pituitary)
  • hepatosplenomegaly
  • growth retardation

 

Langerhans Cell Histiocytosis in a 1-year-old male. A, Lateral radiograph of the skull shows multiple well-defined lytic lesions ("geographic skull"), B, Lateral radiograph of the thoracic spine demonstrates vertebra plana (vertebral destruction with vertebral collapse, arrow), C, AP radiograph of the left distal extremity reveals a lytic lesion in the mid-shaft of the fibula.
Langerhans Cell Histiocytosis in a 4-year-old male. A, AP view of the skull demonstrates multiple well-defined lytic lesions. Note the involvement of the right mandible as well. B, AP radiograph of the pelvis shows lytic lesions (arrows) involving the iliac regions and the proximal femurs bilaterally.
A classic example of "floating teeth" in a child with Eosinophilic Granuloma. Note the bilateral lytic lesions involving the mandible on this panorex view.