PROGNOSTIC SIGNIFICANCE OF PLEURAL EFFUSION IN CHRONIC LYMPHOCYTIC LYMPHOMA: UTILITY OF EARLY FLOW CYTOMETERY IN HEMATOLOGIC PLEURAL METASTASES

Abstract

SESSION TITLE: Fellows Lung Cancer Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pleural effusion in patients with chronic lymphocytic leukemia / small lymphocytic lymphoma (CLL/SLL) is multifactorial in origin (1). Pleural and lung parenchymal involvement by leukemic cells is very rare, but can be a sign of advanced disease, especially, in previously indolent disease (2). High index of suspicion can expedite the workup and potentially can improve clinical outcome in these patients. CASE PRESENTATION: 76-year-old Caucasian male with previous diagnosis of B-cell (CLL/SLL) lymphoma presented with dyspnea and large right sided pleural effusion (Figure 1). CLL was diagnosed two years ago and was treated with Ibrutinib which was recently discontinued due to intolerability. He had not received radiotherapy. Imaging revealed hyper metabolic mediastinal lymphadenopathy without thoracic duct obstruction (Figure 2). Patient had also undergone two prior thoracenteses in which analysis was consistent with an exudative process and cytology was negative (Table 1). Third thoracentesis was done with flow cytometry (FC) which showed monotypic B-cell population consistent with B-cell (CLL/SLL) and was identical to previous lymph node biopsy (Table 2). Indwelling pleural catheter was placed and his symptoms improved with re-expansion of the lung (Figure 1 B). Patient opted for palliative care and died two months later. DISCUSSION: Pleural and lung involvement is rarely seen as initial manifestation of CLL. It can be sign of disease progression in established and indolent CLL (1). Pleural effusion in CLL can be reactive, tuberculous or chylothorax. Radiation or chemotherapy induced serositis causes bilateral pleural and pericardial effusions (1). Very, rarely leukemic cells infiltration produces hemorrhagic effusions (1). However, it can be exudative and non-hemorrhagic, as in this case. Early diagnosis can be challenging in such cases due to coexistent etiologies such as congestive heart failure. Pleural fluid cytology is often inconclusive with mixed B-cell population (2). Identification of monoclonal malignant lymphocyte population identical to primary site is essential. Pleural fluid FC can be helpful in case of in-determinant cytology for confirmation of diagnosis, and is less invasive than pleural biopsy (3). Moreover, it can help to exclude reactive or infectious etiologies, which are T-cell predominant (1). Provider should be aware of limitations of FC in large B-Cell lymphoma (false negative) and T-Cell lymphoma (no specific FC T cell marker) (2). FC should be considered when likelihood of malignancy is high, in-determinant cytology or with previous established diagnosis of CLL. CONCLUSIONS: Refractory pleural effusion in patients with indolent CLL is concerning for disease progression. Pleural fluid cytology is often inconclusive. Early flow cytometry in carefully selected patient population can expedite the diagnosis and thus can minimize the morbidity and mortality. Reference #1: 1-Pleural Effusions in Hematologic Malignancies. Michael G. Alexandrakis, MD; Freda H. Passam, MD; Despina S. Kyriakou, MD; and Demosthenes Bouros, MD, FCCP. (CHEST 2004; 125:1546-1555 Reference #2: 2-Flow Cytometry and Effusions in Lymphoproliferative Processes and Other Hematologic Neoplasias. Beata Bode-Lesniewska. Acta Cytologica 2016; 60:354–364 DOI: 10.1159/000448325 Reference #3: 3-Czader M, Ali SZ: Flow cytometry as an adjunct to cytomorphologic analysis of serous effusions. Diagn Cytopathol 2003;29: 74–78. DISCLOSURES: No relevant relationships by Heather Boakye, source=Web Response No relevant relationships by Hafiz Mahboob, source=Web Response no disclosure on file for Cameron McLaughlin