Your differential diagnoses and frozen section diagnosis?

• The diagnosis is: Leydig cell tumor
• A couple of people have considered " 间质细胞肿瘤". Good job!
• Indeed the cytologic features are very worrisome for a malignant neoplasm on frozen.
• Has to combine with clinical, gross features, and careful microscopic examination to come with the best possible diagnosis. defer for permanent section probably is appropriate for many frozen cases - if a defintive diagnosis can not be rendered.  

Sorry I don't have any more photomicrographs from the frozen slides. But I can assure you that these three pictures do represent what it is look like on frozen sections.

I agree that this case is difficult to interpret...some of the choices I saw are pretty good.

1. Germ cell tumor (seminoma or embryonal carcinoma)

2. DLBCL

3. Leydig cell tumor

4. Metastatic (carcinoma, melanoma)

It's time to make your guess and tell us why.

Will announce the anwer next week!