Adult onset Langerhans cell histiocytosis of the orbit--a case report.

PURPOSE: To report an interesting case of adult onset Langerhans cell histiocytosis in a 41-year-old male with clinicopathological correlation.

DESIGN: Interventional case report.

MATERIALS AND METHODS: A 41-year-old male presented with an ill-defined mass occupying the temporal quadrant of the left orbit. Computerized tomography revealed an ill-defined extraconal mass involving the superolateral aspect of the left orbit with areas of osteolysis involving the lateral and superior orbital walls. The mass excised at orbitotomy showed microscopic features consistent with Langerhans cell histiocytosis. Immunohistochemistry with CD-68 macrophage marker and S-100 was positive, confirming the diagnosis. Treatment included oral steroids and radiotherapy. At 6 months follow-up, he developed a punched-out lytic lesion in the left parietal calvarium. He again received external beam radiotherapy. At 14 months follow-up, he is doing well with no recurrences.

CONCLUSIONS: Adult onset Langerhans cell histiocytosis, though rare, should be included in the differential diagnosis of lytic lesions of the lateral orbital wall in an adult patient.