I am not convinced this is a neoplastic lesion. To me it appears more physiologic than pathologic. Most of photos show an atretic follicle with central vascular structure, a layer of atrophic and splindle granulosa cell layer and a somewhat lutinized theca interna layer which is merging with ovarian stroma. The clue is the prominent eosinophilic and hyalinized so-called "glassy membrane" band in between dark spindle granulosa layer and lutinized theca interna. There are scattered lutinized thecal cells in theca interna with ample pink cytoplasm which are usually seen in childhood or pregnancy. I wonder if this patient has recent pregnancy or abortion history. Please let us know that. In any sense, I will be reluctant to make neoplastic diagnosis based on these photos alone.

On the other hand, there is a large homogenous eosinophilic area in low power photos, but not showing high power pictures. I am curious of the changes in that area and want to make sure we do not miss a spindle cell neoplasm such as ovarian fibroma. Please provide high power photos of those. My guess is that It is most likely just nothing but an area with spindle ovarian stroma.

 Interesting case.

Bin, you have good differential diagnosis.  However I cannot agree with you. I think these cells are neuronal component, but not sex cord stromal components.

The key for this case to dianose immature teratoma or mature solid teratome depends on that the neuroal component is immature and mature.

My feeling is that neuronal component is immature though I am not completely sure that. Need to check books to learn neuronal pathology or get consult from neuropathologists for final diagnosis.

 Chengquan, no offend.  You may be right. But it is so unusual to see an isolated few 'immature neuronal element" in such a clean back ground with no other "teratomatous" changes or components. It is so challenging to render right diagnosis without seeing the whole slide and whole pictures. The view of this case is so focused with lot of high magnifications. I feel there is no way I can call this an "immature teratoma" only based on these pictures. Just my two pennies to arouse further discussion here.

Merry Christmas!

好病例，学习了。请哪位翻译一下。

这些图片非常漂亮

如果这些图片代表的是肿瘤全部或绝大部分。可以确诊为单胚层畸胎瘤。

今天专门请教了我们科搞神经病理的桂秋萍教授，那些围绕血管腔的结构是模拟大脑的胚胎发育过程，相当于大脑皮层，以及蛛网膜下腔。所以即不是神经管，也不是室管膜结构。

这一例诊断不成熟畸胎瘤，不是依据原始神经管成分。是单胚层畸胎瘤，但不是室管膜瘤，而是低倍视野中有一区域由成片的小细胞构成，相当于神经母细胞瘤。

好例子，谢谢分享。