PRIMARY MALIGNANT MYELOMATOUS EFFUSION IN MULTIPLE MYELOMA PATIENT

Abstract

SESSION TITLE: Medical Student/Resident Disorders of the Pleura Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Malignant pleural effusion secondary to Multiple Myeloma (MM) is most commonly a consequence of end organ damage secondary to pleural infiltration with monoclonal gammopathy. It occurs in about 6% of cases of multiple myeloma; approximately 1% of those patients have Primary Malignant Myelomatous Effusion (PMMPE), which occurs due to myelomatous involvement of the pleura or surrounding structures. The diagnosis of PMMPE can be difficult to make with flow cytometry; definitive diagnosis is made with pleural biopsy. CASE PRESENTATION: 53-year-old female with a past medical history of hypertension presented with two months of worsening dyspnea, weight loss, and early satiety. Initial evaluation on admission included a chest x-ray, which showed a large left-sided pleural effusion requiring thoracentesis. Admission laboratory testing showed hypercalcemia and an acute kidney injury, which prompted further diagnostic testing to evaluate for underlying malignancy; which included protein electrophoresis demonstrating markedly elevated free lambda, bone marrow biopsy, which showed 66% plasma cell differentiation, confirming the diagnosis of lambda light chain MM. Her hospital course was complicated by recurrent, rapid re-accumulation of her left-sided pleural effusion requiring two additional thoracenteses. She ultimately had a Pleur-X chronic indwelling chest catheter placed for symptomatic relief. Pleural fluid cytopathology was inconclusive and immunophenotype showed no significant abnormalities. No pleural biopsy was done; however, the initial presentation of a large left-sided pleural effusion would indicate that this was more than likely PMMPE. She was started on outpatient chemotherapy, however her condition continued to deteriorate requiring multiple readmissions, and she unfortunately passed away within four months of initial diagnosis. DISCUSSION: MM is one of the most common forms of cancer in the United States. It represents 10% of all malignant hematological diseases, which mainly affect the bone marrow, although extramedullary tissues may be infiltrated as well. Pleural effusions may be a sign of thoracic involvement in approximately 6%, however 1% of these can be primary pleural effusions. PMMPE is seen very late in the disease process associated with light chain kappa MM, with left-sided effusions being more common. Median survival time after diagnosis is approximately 4 months. Cytological identification of malignant plasma cells within the pleural effusion has been the best test for diagnosis, however due to the limited number of malignant plasma cells and in vitro degeneration, cytological studies can be unreliable. Pleural biopsy may be the most accurate diagnostic test however this can also be inconclusive due to patchy infiltration of pleura. CONCLUSIONS: PMMPE is seen very late in the disease process, can be very difficult to diagnose. Prognosis is poor after diagnosis. Reference #1: Mangla, A., Agarwal, N., Kim, G., Catchatourian, R. Primary Malignant Myelomatous Pleural Effusion. Clinical Case Reports. 2016; 4(8): 803-806. Reference #2: Zhang LL, Li YY, Hu CP, Yang HP. Myelomatous pleural effusion as an initial sign of multiple myeloma—a case report and review of literature. J Thorac Dis 2014;6(7):E152-E159. https://doi.org/10.3978/j.issn.2072-1439.2014.06.48 Reference #3: Xu et al.: A case of bilateral pleural effusion as the first sign of multiple myeloma. European Journal of Medical Research 2013 18:7. https://doi.org/10.1186/2047-783X-18-7. DISCLOSURES: No relevant relationships by Jasmine Sekhon, source=Web Response No relevant relationships by Ximena Solis, source=Web Response No relevant relationships by Divya Vangipuram, source=Web Response