Presentation
3 months of right retroorbital pain/pressure sensation
Patient Data
Lytic lesion in the right anterior clinoid process
The right anterior clinoid process lesion shows STIR hyperintensity and contrast enhancement. The surrounding dura is thickened.
Whole body CT (legs not shown) shows lytic lesions in the right anterior clinoid process (as on prior head CT), right acromion, right third rib, left ilium, and bilateral femora. Lung windows show upper lobe predominant reticulonodular opacities with cystic changes.
Case Discussion
The imaging constellation of multifocal osteolytic lesions (some with well-defined sclerotic margins) and upper lobe pulmonary reticular and nodular opacities and cysts suggested Langerhans cell histiocytosis. Without the pulmonary findings, a reasonable differential would have included myeloma, metastasis, and lymphoma. Serum protein electrophoresis, serum free light chains, and quantitative immunoglobulins were normal.
Skull base lesion resection was performed, with resolution of the retroorbital pressure sensation. Pathology showed patchy chronic inflammation with eosinophils and histiocytoid cells consistent with eosinophilic granuloma. Tumor cells were positive for S100, CD68, CD1A, and langerin.
Final diagnosis: Langerhans cell histiocytosis.