about 60 y/f, right breast mass 2 cm by imaging, breast core biopsy.

1. Your differential diagnosis?

2. What will you do next?

Please do not just give a diagnosis. Your dx is a guess dx even though your diagnosis may be right.

As pathologists we should learn how to analyse our cases with logic thought.We should have differential dx for all cases in our mind even for the easy cases. We can use available sources (such as IHC, molecular methods, history, consultation) to rule in or rule out the differential dx, then make the final dx. 

Learning the priniciple for diagnosis is much more important than learning a few cases.

 同意abin老师的看法，不同意恶性叶状肿瘤

 to　Dr. Zhao:

1. 已知AE1/AE3和Cam 5.2均阴性，Vimentin弥漫强阳性，排除上皮性。Mostly you are right. But you may be wrong. Tell us why.

我这样说是太绝对了。应该说：“AE1/AE3和Cam 5.2均阴性，Vimentin弥漫强阳性，仍不能完全排除上皮性。”

多形性癌：均表达AE1/AE3和Cam 5.2。

腺癌伴梭形细胞化生：表达CK7。

化生性癌或癌肉瘤：其中的异源性化生的梭形细胞成分，可以局灶性表达CK，当然也可能不表达。可以加做CK7和34BE12。

2.也可以等待手术标本再诊断.

Completely do not agree.

这涉及到穿刺标本取材的局限性，是否只取到梭形细胞成分而不见典型的浸润癌成分。正因为如此，我觉得穿刺标本诊断困难时，先报“恶性肿瘤”，等待手术标本再诊断，也许可以避免困难和风险。

不知我的理解是否正确？期盼Dr.Zhao进一步指导。谢谢！

关注

很好的病例，期待结果！

这涉及到穿刺标本取材的局限性，是否只取到梭形细胞成分而不见典型的浸润癌成分。正因为如此，我觉得穿刺标本诊断困难时，先报“恶性肿瘤”，等待手术标本再诊断，也许可以避免困难和风险。

You are right in some points.

We should try to provide clinicians and patients as more information as we can  from the biopsy specimens. It is perfect if we can have final diagnosis in the biopsy specimen. Clinicians can decide next procedure based on pathology diagnosis from biopsy. The treatment plans may be different if this patient has metastatic lesion, melaloma, carcinoma or sarcoma. Of cause we may not make the definite dx sometimes based on the biopsy specimen after we try.

你的部分观点的正确的。

对于活检标本，我们应该努力为临床医生和患者提供尽可能多的信息。如果活检标本能作出最终诊断，它是很完美的。临床医生可以根据活检诊断决定进一步处理程序。如果是转移性病变、恶黑、癌或肉瘤，临床处理方案可能不同。当然，我们有时也可能在尽力之后仍不能根据活检标本作出明确诊断。（abin译）

 In fact it is not very difficult to have the differential dx for this case.
1. The main ddx include sarcoma, carcinoma and others (melanoma, hematologic lesions et al).

2. It is metaplastic carcinoma or basal-like carcinoma if it is carcinoma.

3. What type of sarcoma if it is sarcoma? or just part of malignant phyllodes?

实际上本例的鉴别诊断并不太难。

1.主要鉴别：癌、肉瘤和其它（恶黑、淋巴造血系统病变等）。

2.如果是癌：转移癌或基底样癌。

3.如果是肉瘤：什么类型？或仅仅是恶性叶状肿瘤的一部分？（abin译）

 In your practivce you may not need to do so many cytokeratin stains if we consider the money issue. But at least you need to do a few to rule out metaplastic carcinoma.

Ok, now what is your dx? You want to release the case or you want to do more detailed study if the money issue is not a problem for the patient.

实际工作中低倍可能不需要做这么多CK标记，如果考虑到费用问题。但至少你得做一些排除转移癌的标记。

OK，现在你的诊断？你要发报告还是要做更多研究（如果患者的费用不成问题）？（abin译）

 同意33楼考虑。

已知的免疫组化结果，基本排除癌（原发或转移）。

仅S-100阴性仍不能完全排除恶黑，因此加做HMB45和Melan A。

仅LCA阴性也不能完全排除少见的淋巴造血系统肿瘤，因此加做CD21、CD23、CD68、CD30。

最后可能性比较大的，就剩下肉瘤啦。

叶状肉瘤：ER，PR，Bcl-2，CD117

其它肉瘤：CD31，CD34，Des，……

 More IHC results

SMA

Smooth muscle myosin heavey chain

Muscle specific actin (HHF35)

Desmin

Cd31

Cd34

caldesmon

名称：SMA
描述：SMA

名称：SMHHC
描述：SMHHC

名称：HHF35
描述：HHF35

名称：Desmin
描述：Desmin

名称：Cd31
描述：Cd31

名称：CD34
描述：CD34

名称：caldesmon
描述：caldesmon

 I am sure you know the dx now.

Logic thinking for this case:

1. H@E: malignant.

2 carcinoma (metaplastic or basal-like) vs. sarcoma

3. sarcoma after carcinomas were ruled out.

4. Malignant phyllodes or pure sarcoma

5. what types of sarcoma

 One thing i want to mention is that CD31 is senstitive, but not specific for vascular lesion, CD34 is relative specific for vascular lesion. Of cause many soft tissue tumors and others are positive for CD34. Above case is a good example, CD31 positive, CD34 negative.

D2-40 is good for lymphatic endothelium, often used for confirmoring lymphavascular invasion for breast ca.