This is a great case. I hope you can think more for differential diagnosis when you see a difficult case.

This is a clear cell carcinoma with papillary pattern. I have no any doubt about the diagnosis even though all of you may not believe me.

Please see the papillary architetures with relative uniform nuclei, clear cytoplasam, hobnail cells, even though the latter two features are not classic.  High grade serous carcinomas never show these features. In fact this tumor may be easily to be confused with low grade serous carcinoma or borderline serous carcinoma if it is in ovary.

It is not necessary to do the IHC for this case. Genearlly P53 and WT1 are positive for most of serous  carcinomas. Clear cell carcinoma may also positive for both even though most of clear cell carcinomas are negative for wt1 and p53.

I did a study of ovarian celar cell carcinoma and once read many times for 500 cases of clear cell carcinoma (more than 8,000 slides). I may be the number one person in the world to read so many cases of clear cell carcinoma. Please trust my diagnostice skill.

Please do not be sad about your diagnosis. Most general patholoigists in the US will make the same diagnosis as yours.

Thank again for hodgkin for the good case. You are great you can pick up the case. I do not know what is your first diagnosis or impression about the case. However I am sure that you feel it is not a typic serous carcinoma at least.

abin译：

这是个非常好的病倒。我希望你们见到一个疑难病倒时，能想到更多的鉴别诊断。
这是有乳头结构的透明细胞癌。我对此毫不怀疑，尽管你们可能不相信。
请看，乳头结构由相当一致的核组成，胞浆透明，鞋钉状细胞，尽管后两个特征不太典型。高级别浆液性癌从不出现这些特征。实际上，这一肿瘤很容易与低级别浆液性癌或交界性浆液性癌混淆 if it is in ovary。
本例不一定必须做IHC。大多数浆液性癌一般p53和WT1阳性。尽管透明细胞癌的p53和WT1大多数呈阴性，但也可二者均阳性。
我做过一项关于卵巢透明细胞癌的研究，共有500例（超过8000张切片），阅片许多次。我可能是全世界看过透明细胞癌例数最多的人。请相信我的诊断水平。
请不要对你们自己的诊断感到沮丧。美国的大多数大外科病理医生也会作出同样诊断。
再次感谢Hodgkin提供如此好的病例。你能挑选出为一例就很了不起。我不知道你的第一诊断或初步印象是什么。然而我确信你感觉到这例至少不是一个典型的浆液性癌。

 这一例的免疫表型是ER 部分阳性，PR阴性，P53强阳性，KI67  80%阳性。