Bilateral Orbital Plasmacytomas With Orbital Compartment Syndrome

Orbital plasmacytomas are uncommon soft-tissue plasma cell neoplasms that are associated with a monoclonal or myeloma protein. There are four types of plasma cell neoplasms: multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), amyloidosis, and plasmacytoma. Plasmacytomas may be classified as medullary, occurring only within the bone, or extramedullary, occurring in soft tissues. Orbital plasmacytomas are extramedullary manifestations associated with MM and they may present with signs and symptoms such as unilateral proptosis, conjunctival injection, ocular pain, diplopia, and vision changes. The diagnosis of orbital plasmacytomas is based on tissue biopsy and histologic and immunohistochemical confirmation of a homogenous infiltrate of monoclonal plasma cells. In this report, we present a case of a 60-year-old female patient with a prior diagnosis of MM and new-onset bilateral orbital plasmacytomas following an autologous peripheral blood stem cell transplant; her condition improved significantly following treatment with dexamethasone, cisplatin, doxorubicin, cyclophosphamide, and etoposide along with palliative radiation therapy (RT) of 2000 cGy in 10 fractions to the orbits. Unfortunately, three months later, she had progression of extramedullary disease with parotid gland involvement. She had multiple complicated hospitalizations and eventually expired. As patients with orbital plasmacytomas classically have lower remission and survival rates compared to those with extramedullary plasmacytomas involving other locations, they must be considered high-risk patients who require a multidisciplinary approach for early diagnosis and timely treatment in order to prevent disease progression and to alleviate symptoms related to the disease.