Unusual manifestations of Langerhans cell histiocytosis of the head and neck. Case report with pseudoaneurysm of external carotid artery, tracheal, mandibular, and sphenoid involvement.

Langerhans cell histiocytosis of the head and neck is an uncommon histiocytic proliferative disorder that often clinically resembles an inflammatory process. A pseudoaneurysm of the external carotid artery was found by contrast-enhanced CT and confirmed by Doppler ultrasonography and angiography in a 9 year old girl with a lytic lesion of the mandible, a prior severe tracheal inflammatory process, and sclerotic lesions of the sphenoid wings. Biopsies of the mandibular lesion, pseudoaneurysm, and trachea demonstrated Langerhans cell histiocytosis. In cases of LCH with head and neck involvement, contrast-enhanced CT allows adequately detailed initial evaluation of the protean manifestations of this disorder.