Table 2 Diagnostic criteria of LCH

Based on clinic-pathological evidence with microscopic examination and at least one of the following immunological staining:

Based only on clinico-radiological evidence, without biopsy, as in case of:

• Langerin (CD 207) positivity

e.g.: Pulmonary lesions on CT scan with typical cysts and nodules in a smoker. (however, biopsy should be considered in order to reach a more definitive diagnosis)

• CD1a positivity

• Presence of Birbeck granules on electronic microscopy