Malignant Mesothelioma - How Reliable to Make the Diagnosis on Cytology: Single Academic Center Experience

Abstract

diagnosis to metastasis ranged from 0 to 12 (median 0.8) years. Seven (50%) were urothelial carcinomas, characterized by cytoplasmic vacuolization (100%), multinucleation(83%), dense cytoplasm(83%), signet ring cells(50%) (Figure 1a), cell wrapping (33%) (Figure 1b), and cell windows (33%). No cercariform cells were seen. Six (43%) were renal cell carcinomas which exhibited cytoplasmic vacuoles (100%) (Figure 2a), prominent nucleoli (83%) (Figure 2b), granular (67%) and clear cytoplasm(50%). One case of malignant ascites was secondary to metastatic bladder leiomyosarcoma. No metastatic prostate cancers were identified. Six (43%) involved the peritoneum, 6(43%) were pleural, and 2(14%) were in the CSF. None were detected in the pericardium. Immunohistochemical staining was utilized to confirm 4 urothelial and 3 renal cell carcinoma cases. Conclusion: Metastatic GU cancers in serous cavities are rare, comprising only 0.2% of all effusions and 1.0% of all malignancies. To our knowledge, this is the first case of metastatic bladder leiomyosarcoma in ascites diagnosed by effusion cytology.