Association of Multiple Myeloma and Giant Cell Arteritis - A Case Report.

Autoimmune diseases (AID) have been associated with a variety of lymphoproliferative disorders. Multiple myeloma (MM), one of the most common haematologic malignancies characterized by clonal proliferation of bone marrow plasma cells, has been associated with a range of autoimmune disorders. In this report, we described a case study of a patient admitted to our Internal Medicine Department for a bone marrow biopsy and myelogram due to a monoclonal peak observed by his general practitioner. However, at admission he presented typical giant cell arteritis (GCA) complaints, suggesting the coexistence of both diseases. The possible pathogenesis, as found in the literature, explaining the association will be discussed. LEARNING POINTS A relationship between AID and lymphoproliferative diseases, although rare, may occur and some studies suggest that the diagnosis of autoimmune disease has a negative impact on survival in MM patients. Bone marrow plasmacytosis can present a diagnostic dilemma, since it may be due to neoplastic or non-neoplastic conditions (that is, reactive plasmacytosis associated with AID, chronic infection, metastatic carcinoma, liver diseases and acquired immunodeficiency). Immunophenotyping in a myelogram or immunohistochemistry in bone marrow studies are useful in confirming a monoclonal plasma cell proliferation. Keywords: Giant cell arteritis, multiple myeloma, autoimmunity INTRODUCTION Multiple myeloma (MM) is a plasma cell disorder characterized by clonal proliferation of bone marrow plasma cells[1]. The aetiology is poorly understood but there is some evidence that immune dysregulation or sustained immune stimulation plays an important role in the pathogenesis of this disease. Therefore, the incidence of MM or monoclonal gammopathy of undetermined significance (MGUS) is higher in patients with a history of autoimmune diseases (AID)[2,3]. Giant cell arteritis (GCA) is a chronic vasculitis of medium- and large-sized vessels that involves particularly extracranial branches of the aortic arch arteries. There is a higher incidence in patients over 50 years of age and it is usually characterized by headaches, fatigue, low-grade fever, jaw claudication during mastication, loss of vision, scalp tenderness, polymyalgia and acute loss of vision[4]. The relationship between AID and lymphoproliferative diseases is described in the literature.