Case of the Month: Cytopathology
April 2017 Case of the Month authored by Cytopathology Unit Director Marino Leon, M.D., FCAP, FASCP
A 65-year-old male presented with right pleural effusion; focal pleural thickening was identified by computerized tomography (CT) scan. A pleural fluid aspiration was submitted to the University of Florida Health Pathology Laboratories Cytopathology Laboratory.
Figure 1: Cluster of cells with irregular edge (Papanicolaou stain)
Figure 2: Group of cells with tridimensional architecture; the cells show high nuclear-to-cytoplasmic ratios and cells with irregular nuclear outlines (Papanicolaou stain).
Figure 3: Spherical cluster of cells with irregular nuclear outlines and nuclear grooves (hematoxylin and eosin; cell block)
Figure 4: The tumor cells are positive for MOC-31 immunostain.
Figure 5: The tumor cells are positive for TTF-1 immunostain.
(Hover the cursor over the link above to read the diagnosis for this case.)
Key cytopathologic features:
- Groups of cells in the fluid, usually showing a smooth edge (i.e., community border)
Cells with sharp cytoplasmic edges
- Lack of double edges or fuzzy cytoplasmic edges
- Lack of intercellular spaces (i.e., windows)
- Cytoplasmic vacuoles and signet ring cells
- MOC-31, berEP4, and monoclonal CEA positive
- Expression of thyroid transcription factor-1 (TTF-1) and napsin-A
- The cells may express cytokeratin 5/6 and p63, focally.
- These cells are negative for calretinin, D2-40 and WT-1.