A Case of Multiple Myeloma: Rare Presentation as Ascites

Abstract

Introduction: Ascites is a rare complication of multiple myeloma (MM). Most reported cases have been associated with IgA type of myeloma. Here, we describe a case of IgG type MM. Case Report: A 58-year-old male nonalcoholic with hx coronary heart disease, hyperlipidemia was hospitalized for increasing abdominal distension associated with dyspnea. Examination revealed grossly distended abdomen with shifting dullness. Labs: Hb 8.5g/dL, Hct 25.8%, WBC 36.2K/mm3 (granulocytes 47%, lymphocytes 13%, monocytes 38%); platelets 281K/mm3, BUN 34mg/dL, Cr 1.7mg/dL, Ca 8.1mg/dL, PO4 3.6mg/dL, serum albumin 2.7g/dL, total protein 6.9g/dL, and other liver chemistry is normal. Ascitic fluid - orange, bloody appearance, rare mesothelial cells and lymphocytes with numerous highly atypical cells positive for CD 138, CD 117 and CD 45; WBC 175/mm3,RBC 15,500/mm3, ascitic fluid albumin 2.5g/dL and total protein 5.4g/dL. SPEP showed IgG level 4620mg/dL (normal 8-16) and IgA 31mg/dL (normal 68-423). CXR were normal, and skeletal survey showed lucent lesions in the lumbar spine. Flow cytometry revealed 37% abnormal lambda restricted plasma cells expressing CD 38 and 138. Bone marrow aspirate showed hypercellular marrow (100%) with marked plasmacytosis (90%) consistent with plasma cell myeloma. A diagnosis of multiple myeloma (MM) with plasma cell ascites was made, and the patient was started on treatment with dexamethasone, bortezomib, cisplantin, doxorubicin, cyclophosphamide, and etoposide with a good response. Discussion: MM is a neoplastic proliferation of malignant monoclonal plasma cells. Extramedullary incidence rate is rare, 4%. The most common sites for extra medullary plasmacytoma (EMP) are the upper respiratory tract, reticuloendothelial system, kidneys, and gastrointestinal (GI) tract. The GI tract is the site of origin in about 10% of the cases. The small bowel is the most common site of involvement, followed by colon, stomach, esophagus, and peritoneum. Plasma cell ascites is usually associated with extensive liver infiltration with plasma cells and myelomatous peritoneal infiltration. Peritoneal myeloma cell infiltrates proven by biopsy are extremely infrequent. These patients usually have IgA monoclonal spike. The GI involvement at the time of initial diagnosis of MM is much rarer than later in the course of the disease, and often develops in patients with relapsing disease after stem cell transplantation. Extramedullary progression of MM and monosomy 13 are associated with worse prognosis. This case is unique, as the patient was diagnosed with plasma cell ascites with IgG monoclonal spike.