Read above argument about adeno or squamous ca. Some times it is difficult to tell squamous ca from adenocarcinoma in cytology. However it is very easy by using IHC.

For this case if we can rule out mesothelial origin (calretinin negative), then we know it is a cancer case.

Next step we need to figure out the possible origin, including squamous vs adeno.  How? We need IHC stains

P63, ck5/6 for squamous ca, mucicarmin stain for adenocarcinoma

CK7/ck20

TTF1

Of cause we need to have clinial correlation with imaging results

 倾向于鳞状细胞癌。在胸水中，腺癌占到80%以上，鳞癌还不到5%，所以在胸水中见到癌细胞，归入腺癌正确的几率很高。

该例仔细观察，细胞没有腺癌常见的球团状结构，细胞之间更趋向于平铺，细胞核无明显的偏位，而是较为居中，胞浆较为实性，这些都是鳞状细胞癌的特点，所以倾向于鳞状细胞癌。

 真不好分

 此例考虑为鳞癌细胞．

具体鉴别方法请参考下列标准：

细胞排列：腺癌细胞立体感，腺腔样，球样，而鳞癌细胞平铺状；

细胞形态：前者圆形卵圆形，大小相仿，而后者不规则形，大小相差悬殊；

染色质：前者粗颗粒，后者炭块状；

核仁：前者常见，后者少见．

核位置：前者偏位，后者居中；

核形态：前者圆形卵圆形，大小相仿，而后者不规则形，大小相差悬殊．

胞浆：前者常见粘液泡，后者可见角化．