Macroscopy: Pleural fluid- 700ml of blood-stained fluid.
Microscopy: The preparations show blood, chronic inflammation, histiocytes, mesothelial cells and numerous malignant epithelioid cells presenting in cohesive arrangements and large papilliform fragments. These cells are pleomorphic, exhibiting a high N/C ratio, convoluted nuclei, coarsened chromatin, macronucleoli and moderate amount of vacuolated cytoplasm.
Conclusion: Pleural fluid: Malignant. Features consistent with metastatic adenocarcinoma.
Diffusely positive for CK7 and TTF1, weak positive GATA3, negative CK20, ER, PAX8, HER-2 – pulmonary origin