A Rare Case of Myelomatous Ascites with ESKD

Introduction: Ascites is seen in less than 1% of patients with multiple myeloma (MM) and can be difficult to manage in the setting of concomitant kidney disease. Literature review revealed that myelomatous ascites has never been described concomitantly with end-stage kidney disease (ESKD). Here we describe an ESKD patient with relapsing MM presenting with refractory ascites. Case Description: A 63-year-old African American male presented in February 2023 with acute kidney injury. He was initiated on hemodialysis (HD). Bone marrow biopsy showed more than 90% plasma cells. Flow cytometry showed lambda-restricted plasma cell myeloma. He was treated with CyBorD regimen (cyclophosphamide, bortezomib, dexamethasone). An autologous bone marrow transplant was done in November 2023 and showed relapse proven by bone marrow biopsy in January 2024. He presented with ascites in April 2024. Laboratory tests revealed decreased total protein but normal levels of albumin, ALT, AST, ALP, and total bilirubin. CT abdomen/pelvis showed a large amount of ascites with infiltration of the omentum. Paracentesis was done multiple times. Peritoneal cytology and flow cytometry showed CD138-positive plasma cells. Serum ascites albumin gradient (SAAG) was 1.4 g/dL, total nucleated cell count of 2742, and 2.8 g/dL total protein. Persistent hypotension prevented ascites control in spite of albumin use with hemodialysis. Discussion: Myelomatous ascites is present in less than 1% of non-dialysis patients and significantly reduce the life expectancy. Rare cases of myelomatous ascites with acute kidney injury were previously described. ESKD patients dependent on HD have never been reported to have myelomatous ascites. It should be considered as a cause of ascites after other etiologies are excluded. Multiple studies showed SAAG is being helpful in diagnosing ascites with more than 90% sensitivity and specificity. A SAAG of less than 1.1 g/dL is expected in myelomatous ascites. However, in our case, SAAG was 1.4 g/dL on two different measurements. The presence of ascites makes dialysis ultrafiltration challenging without much benefit. In our case, abdominal paracentesis was helpful for immediate relief.