Cytopathology of malignant melanoma in conventional and liquid-based smears

We evaluated 62fine-needle aspiration (FNA) biopsy specimens of metastatic malignant melanoma (MM) from 62 patients and compared 84 smears with the corresponding tissue sections. Melanin is found more often in FNA smears than in corresponding tissue sections of metastatic MM but is significantly less abundant in smears. Melanin is present more often in liquid-based than in conventional smears. Pseudoinclusions were almost twice as frequent in tissue sections as in corresponding aspirates, regardless of the preparation method. There was no statistical difference for cell type or cytoplasmic features in the tissue sections and aspirates or between the type of preparation and/or stain used. With the exception of melanin, direct comparison of liquid-based and conventional smears showed higher cellularity in the former as the only difference.