Non-gynaecological Cytology
Effusions cytology
| Physiopathology of the effusions |
| Specimen collection and preparation methods |
| Accuracy |
| Reporting terminology |
| Benign elements |
| Non-neoplastic conditions |
| Malignant effusions |
Malignant melanoma
- Dispersed tumor cells
- Brown melanin pigment
- Binucleated (mirror image)
In effusions the malignant cells of metastatic melanoma resemble mesothelial cells: they are often dispersed as isolated round cells with prominent nucleoli. In some cases, they show a fine brown cytoplasmic pigmentation and intranuclear inclusions. Cell clusters are uncommon.
Immunocytochemistry is helpful when the distinction from reactive mesothelial cells is difficult: melanomas are positive for S-100 protein and HMB-45 and negative for keratin proteins.
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