Phagocytic Mesothelial Cells in Pericardial Effusion Following Allogeneic Peripheral Blood Stem Cell Transplantation...

Area of Science:

• Oncology
• Hematology
• Cell Biology

Background:

• Phagocytic activity in mesothelial cells is uncommon and requires differentiation from histiocytic hemophagocytosis due to differing clinical implications.
• Allogeneic peripheral blood stem cell transplantation (SCT) is a treatment for various hematologic malignancies and immune disorders.
• Chronic active Epstein-Barr virus (EBV) infection can necessitate SCT and may be associated with complications like graft-versus-host disease.

Purpose of the Study:

• To report a rare case of phagocytic mesothelial cells in pericardial effusion.
• To emphasize the importance of accurate diagnostic methods in post-transplantation settings.
• To differentiate phagocytic mesothelial cells from other hemophagocytic syndromes.

Main Methods:

• Cytological examination of pericardial effusion.
• Berlin blue staining for hemosiderin.
• Immunocytochemical analysis including pan-cytokeratin (AE1/AE3), calretinin, desmin, and CD163.
• Monitoring of ferritin levels and EBV DNA in peripheral blood.

Main Results:

• Mesothelial cells with intracytoplasmic lymphocyte-like structures and hemosiderin were identified.
• Immunocytochemistry confirmed mesothelial origin (pan-cytokeratin, calretinin, desmin positive; CD163 negative).
• Patient had favorable clinical course with undetectable EBV DNA and no recurrent effusion.

Conclusions:

• Phagocytic mesothelial cells can occur in pericardial effusion after SCT for EBV infection.
• Distinguishing these cells from histiocytic hemophagocytosis is critical for patient management.
• Integrated cytomorphological and immunocytochemical evaluation is essential for accurate diagnosis.