case_images: PMC8323422_01
case_images: Body fluid scattergram. WBC differential fluorescence (WDF) scattergram of the
  patient's pericardial effusion showed high fluorescent cells
  (HF-BF# = 0.132 x 109/L). The greater dispersion of these cells reflects a
  wide heterogeneity of nucleic acid content and internal cell structure (red
  ellipse).. SFL: side fluorescence; SSC: side scatter.
case_images: 10.1177_2050313X211036005-fig1.jpg
case_images: PMC8323422_01_10.1177_2050313X211036005-fig1.jpg
case_images: fig1-2050313X211036005
case_images: Interestingly, cells suggestive of malignancy were considered, as the Sysmex XN-1000 hematology analyzer (Sysmex, Kobe, Japan) showed a wide group of highly fluorescent cells that were quite distinct from the white blood cell (WBC) clusters (Figure 1), with a high-fluorescence body fluid (HF-BF%) of 5.2% and HF-BF count of 0.132 x 109/L (no cut-off available).
case_images: Cytological morphology. Cytomorphological analysis on the collected pericardial
  effusion was carried out after a cytospin and the May-Grunwald-Giemsa staining method.
  It highlighted giant basophilic cells compared to a normal neutrophil (a). Some cells
  accumulated numerous morphological characteristics typical of malignancy including
  multinuclearity (b), nuclear blebs (c), several large irregular nucleoli (d),
  asymmetrical mitotic figure (e), and images of cannibalism (f). No acute inflammatory
  cells were visualized. Magnification: 100x.
case_images: 10.1177_2050313X211036005-fig2.jpg
case_images: PMC8323422_01_10.1177_2050313X211036005-fig2.jpg
case_images: fig2-2050313X211036005
case_images: Cytology performed in the hematology laboratory revealed 4% neoplastic cells based on typical morphological abnormalities observed after a cytospin and the May-Grunwald-Giemsa staining method, thus allowing the diagnosis of pericardial carcinomatosis (Figure 2).
case_images: CT scan. Pericardial tumor nodules (blue arrow) were seen on the CT scan performed at
  further tumor progression 2 months after the acute cardiac failure.
case_images: 10.1177_2050313X211036005-fig3.jpg
case_images: PMC8323422_01_10.1177_2050313X211036005-fig3.jpg
case_images: fig3-2050313X211036005
case_images: TTEs found the relapse of a loculated pericardial effusion, and later, the occurrence of solid pericardial nodules on computed tomography (CT) scan confirmed the malignant origin of the pericardial effusion (Figure 3). This tumor infiltration of the pericardium was considered as secondary to the lung adenocarcinoma, as the patient initially had locally advanced disease, characterized by a lymphangitic carcinomatosis and a pleural infiltration.