• Written By: Jennifer Doyle, MD

    The authors report two cases of biopsy-confirmed Erheim-Chester disease (ECD) presenting with homonymous hemianopia.

    They also review the positive immunohistochemical staining seen in ECD and discuss the treatment of ECD, as well as histopathological and immunohistochemical differentiation from other histiocytic disorders.

    ECD is a rare non–Langerhans cell histiocytosis typically affecting multiple organ systems. Central nervous system involvement is seen in fewer than 50% of patients, and visual defects usually involve the anterior visual pathway.

    Both patients developed homonymous hemianopic visual field defects because of the unusual occurrence of ECD involving the posterior visual pathways. One patient is the third known ECD case with isolated intracranial involvement.

    Diagnosis was delayed in both patients because of the unusual presentation and initial nondiagnostic biopsy results.