Orbital Plasmacytoma Mimicking an Orbital Abscess.

An 83-year-old male with a 15-month history of multiple myeloma presented with acute onset of swelling, redness, and pain around his right eye. CT scan was consistent with an orbital abscess. The patient was taken to the operating room for drainage of the orbital abscess. Abnormal tissue was encountered intraoperatively so biopsies were taken. His cultures grew only one colony of coagulase-negative Staphylococcus aureus. The histopathology from the biopsies showed a CD-138 positive plasma cell neoplasia consistent with a plasmacytoma. Plasmacytomas have been reported to present as orbital cellulitis and as abscesses in other locations in the body, but to our knowledge, this is the first case of a plasmacytoma presenting as an orbital abscess.