Orbital involvement in Castleman disease.

Castleman disease is a quite uncommon lymphoproliferative disorder usually occurring in the lymph nodes. Rarely, Castleman disease develops in an extranodal anatomic location. We report on the first biopsy-proven case of multicentric plasma cell type of Castleman disease involving the orbital areas in a human herpes virus 8 (HHV-8)-unassociated/ human immunodeficiency virus (HIV)-seronegative 70-year-old man suffering from Parkinson disease. The diagnosis was established on the basis of morphologic, immunophenotypic, and molecular findings of a lymph node and orbital soft tissue biopsy. We additionally provide a review of all previously published cases of Castleman disease with an orbital involvement, discussing the distinctive characteristics and potential associations with regard to their counterparts at other sites. Although Castleman disease involving the orbit is an exceptionally rare occurrence that may present initially with ocular signs and symptoms, this should be included in the complete differential diagnosis of orbital mass lesion.