case_images: PMC5259935_01
case_images: (a) Fine needle aspiration smear show lymphoid population admixed with signet ring cells (arrow, Leishman stain, x400). (b) IgG cytoplasmic positivity in signet ring cells. (arrow, immunofluorescent stain, x400). (c) Pleural fluid show lymphocytes, mesothelial cells (arrowhead), and signet ring cells (arrow, H&E, x400). Inset shows HBME1 cytoplasmic positivity in mesothelial cells (arrowhead), with negative staining in signet ring cells (arrow, immunocytochemical stain, x400). (d) Histology highlighting the follicular architecture (H&E, x40)
case_images: JCytol-34-56-g001.jpg
case_images: PMC5259935_01_JCytol-34-56-g001.jpg
case_images: F1
case_images: The background showed lymphoglandular bodies [Figure 1a]. To our surprise, the signet ring cells gave brilliant fluorescence for IgG antibody [Figure 1b]. These signet ring cells showed negativity for the mesothelial marker HBME1on immunocytochemistry [Figure 1c]. The lymph node biopsy showed classical follicular lymphoma with some diffuse areas [Figure 1d].
case_images: (a) Histology show inter follicular area showing signet ring cells (arrow H&E, x400). (b) CD 45 positivity (CD45, x100). (c) Pan-cytokeratin show negative reaction (PanCK, x400). (d) CD 20 positivity (CD20, x400)
case_images: JCytol-34-56-g002.jpg
case_images: PMC5259935_01_JCytol-34-56-g002.jpg
case_images: F2
case_images: The signet ring cells were seen mostly in diffuse areas and interfollicular areas [Figure 2a, arrow].