70岁  男性

一侧胸腔积液来就诊

CT显示肺不张、大量积液

 见高度核异质细胞,疑癌。

年老患者单侧血性胸水是凶多吉少。可是，细胞相对比较弥散，很难见到粘着成团成蔟的、乳头状的或腺样的结构。甚至许多细胞可能是增生的间皮细胞。需要再送胸水复查，必要时制作细胞块做IHC标记鉴别诊断。

To be or not to be, 

Need immunostain to confirm. don't go too fast.

 高度疑癌,免疫细胞化学染色确诊

Agree above. Do two stains, BerEp4 (for epithelial cells) and calretinin (间皮细胞) if you can. Mostly you can get the answer. If both are negative, do CD68 (histiocytes) and LCA (WBC, lymphocytes).

I cannot make definite diagnosis if IHC cannot be performed.

Dr. Zhao has found the key feature of the cytology. If you want to make a definite diagnosis of adenocarcinoma, the 3-D particles of cells ARE VERY IMPORTANT. For the mesothelial cell might mimic the morphology of tumors as you want.

To my knowledge, I can not call it a tumor or metastasis.

是的。但的确有个别细胞不好解释；老年单侧血性胸水，还是要引起注意。所以建议复查，并做细胞块，然后经IHC标记来加以鉴别。

不用可疑，是腺癌细胞。