Langerhans Cell Histiocytosis With Orbital Involvement

To review three cases of Langerhans cell histiocytosis with orbital involvement that represent a significantly excessive incidence of this rare disease in one community. Current diagnostic criteria and therapeutic modalities related to Langerhans cell histiocytosis are reviewed. Case reports. We present clinical, radiologic, histopathologic, and epidemiologic information on three patients with Langerhans cell histiocytosis. All three children, born within 18 months of one another, manifested rapidly progressive unilateral proptosis at age 2 years. By computed tomography, all had moderately enhancing lesions with involvement of the sphenoid bone and lateral orbit as well as the temporal lobe of the brain. All patients were treated with a combination of vincristine and prednisone, with variable resolution of their lesions. The occurrence of three cases in children born in Nogales, Arizona/Mexico, suggests an incidence rate of 40 per million, which is approximately 26 times the expected rate (P = .0001). The extraordinarily high incidence and the concentration of cases in both time and space of this cluster implies that Langerhans cell histiocytosis may be a sentinel disease for unusual environmental exposures.