The Open Breast Cancer Journal

2011, 3 : 49-52
Published online 2011 December 14. DOI: 10.2174/1876817201103010049
Publisher ID: TOBCANJ-3-49

Metastatic Lobular Carcinoma of the Breast in Pleural Fluid: Diagnostic Pitfall for Mesothelial Cells

Yoon Mi Jin , Sharon L. Hirschowitz and Sophia K. Apple
Department of Pathology, David Geffen Medical Center, 10833 Le Conte Ave CHS 1P-244, Los Angeles, CA 90098-1732, USA.

ABSTRACT

Cytomorphologic patterns of breast carcinoma in effusion include three-dimensional groups of tightly packed clusters for invasive ductal type and single files with cytoplasmic signet ring-like cells for invasive lobular type. A mesothelial-like cell pattern has been described for metastatic lobular carcinoma in pleural fluid. We report a case of a patient with a remote history of lobular carcinoma of the breast who presented with hypocellular pleural effusion with the mesothelial-like cell pattern. Without the previous clinical history and the help of marker studies, the mesothelial-like cell pattern of metastatic lobular carcinoma to pleural fluid may be difficult to distinguish from benign reactive/atypical mesothelial cells.