ORBITAL IMMUNOCYTOMA SIMULATING HODGKINS-DISEASE BY MIMICKING HODGKIN-LIKE AND REED-STERNBERG-LIKE CELLS

Purpose. The present case report describes primary orbital immunocytom a (IgM-kappa) mimicking Hodgkin's disease of the diffuse, lymphocyte p redominance type by expressing Hodgkin simulating cells as well as Ree d-Sternberg simulating cells (both: H-RS cells). Patients and methods. The patient (87a; male) was admitted to hospital with increasing left upper eyelid protrusion. Computed tomography revealed an unspecific a ccumulation of soft tissue within the orbit. A biopsy was taken. Light microscopical sections were stained with PAS, Giemsa and haematoxylin -eosin. Immunohistochemistry was performed following standard procedur es. Results. By means of light microscopy, Hodgkin's disease of the di ffuse, lymphocyte predominance type was indicated. This initial diagno sis was mainly based on morphological criteria, e.g. the presence of H -RS-like cells. Since staging work-up produced no evidence of systemic disease, immunohistochemistry was performed. It revealed that the mis leading cells were H-RS simulating cells. Finally, the diagnosis made was that of immunocytoma (IgM-kappa); stage I EA. Conclusion. The diag nosis of Hodkin's disease of the diffuse, lymphocyte predominance type is normally based on morphological criteria. However, in very rare ca ses immunocytomas simulate this variant of Hodgkin's disease by expres sing misleading H-RS simulating cells. Thus, immunohistochemical inves tigations should generally be included in the criteria for the diagnos is of Hodgkin's disease of the diffuse, lymphocyte predominance type. As far as we are aware, primary immunocytoma mimicking this variant of Hodgkin's disease within the orbit has never been reported.