Multisystemic Langerhans cell histiocytosis with advanced lung involvement.

Langerhans cell histiocytosis is a rare disease of unknown cause, characterized by the proliferation of histiocytic cells (Langerhans cells), that can sometimes be especially difficult to diagnose due to its wide clinical spectrum, ranging from a single lesion to a multisystemic disorder. Appropriate disease staging is fundamental, since treatment depends upon the severity of the disease, and imaging methods play a fundamental role not only in diagnosing and assessing the extent of Langerhans cell histiocytosis, as well as guiding the appropriate treatment for the patient and their monitoring.