Pleural effusion cytology of metastatic papillary rcc mimicking papillary carcinoma of thyroid: an interesting case report

Malignant Pleural effusion in renal cell carcinoma is rare and pleural fluid cytology is necessary for its diagnosis. Though tumour cells are shed more in effusion fluid, good cytomorphology and clinical correlation are essential for accurate diagnosis. Here the author misinterpreted the malignant pleural effusion secondary to papillary renal cell carcinoma with that of papillary carcinoma of thyroid due to the presence of artifactual intra nuclear inclusion. Detailed clinical history and additional cell block section morphology helped to arrive at accurate diagnosis. It emphasizes the importance of clinical details and supplementary cell block study for improving the diagnostic accuracy of malignant effusion.