To  路在何方,

Thank you for sharing this case and your discussion about basal-like ca. Happy to know that you are a very considerable pathologist and have a lot of knowdge on basal-like ca.

I totally agree with your dx of basal-like ca based on the definition.

Basal-like carcinoma is a relative new term based on gene expression profiling studies. It can be identified using an IHC panal, triple negative (ER/PR/Her2) and positive for one or several basal-like markers (ck5/6, CK14, ck17, 34b-E12, EGFR).

In fact most cases of metaplastic carnoma belong to the spectrum of basal-like carcinomas based on the definition, such as spindle cell ca, squamous cell ca, adenosqumous.

Basal-like carcinomas include several different subtypes. Currently we call metaplastic ca if the cases have classic of metaplasic components, such as spindle cells, squamous cells, chondro-osseous. To typical basal-like ca we call invasive ductal carcinoma with basal-like phenotypes.

Fibromatosis-like spindle cell carcinoma also belongs to the spectrum of basal-like ca. However, unlike most basal-like tumors, FLSpCC is not associated with an unfavorable clinical prognosis.

Another concept is that triple negative ca is not identical to basal-like ca even though most triple negative carcinomas are basal-like ca.

The importance is that the clinicians or surgens know the meaning of the terms of pathologic diagnosis. Pathologists have the duty to educate the clinicians.  

感谢你分享这个病例和关于基底细胞样乳腺癌的讨论。很高兴了解到你是个非常善于思考的病理医生，并且对基底细胞样乳腺癌非常熟悉。

我完全同意你的诊断------基底细胞样乳腺癌。基底细胞样癌是个相对较新的基于基因表达分析的诊断术语。它可以通过免疫组织化学方法来识别，ER  PR Her2三阴性和一种或几种基底细胞样指标阳性（ck5/6, CK14, ck17, 34b-E12, EGFR）。实际上，按照定义大多数化生性癌属于基底细胞样癌的范围，如：梭性细胞癌、鳞状细胞癌和腺鳞癌。基底细胞样癌包括几个亚型。一般，如果病例中有典型的化生成分，如：梭形细胞，鳞状细胞、软骨，我们则称之为化生性癌。对典型的基底细胞样癌我们称之为具有基底细胞样表现的浸润性导管癌。纤维瘤病样梭形细胞癌也属于基底细胞样癌的范围。然而，与大部分基底细胞样肿瘤不一样，fibromatosis-like spindle cell carcinoma 临床预后not bad。另外一种观念是三阴性的癌不等同于基底细胞样癌，虽然大部分三阴性癌是基底细胞样乳腺癌。

  重要的是临床医生或外科医生要知道病理诊断名称的含义，病理医生有义务让临床医生了解它。

Thank above translation, cz

Metaplastic breast carcinomas are basal-like tumours.

Original article

Histopathology. 49(1):10-21, July 2006.
Reis-Filho, J S 1,2; Milanezi, F 2,3; Steele, D 1; Savage, K 1; Simpson, P T 4; Nesland, J M 5; Pereira, E M 6; Lakhani, S R 4; Schmitt, F C 3,7

Abstract:
Aims: Recently, an immunohistochemical panel comprising antibodies against HER2, oestrogen receptor (ER), epidermal growth factor receptor (EGFR) and cytokeratin (CK) 5/6 was reported to identify basal-like breast carcinomas, as defined by cDNA microarrays. Our aim was to analyse a series of metaplastic breast carcinomas (MBCs) using this panel plus two other basal markers (CK14 and p63) and progesterone receptor (PR), to define how frequently MBCs show a basal-like immunophenotype.

Methods and results: Sixty-five cases were retrieved from the pathology archives of the authors' institutions and reviewed by three of the authors. Immunohistochemistry with antibodies for HER2, ER, EGFR, CK5/6, CK14 and p63 was performed according to standard methods. All but six cases (91%) showed the typical immunoprofile of basal-like tumours (ER- and HER2-, EGFR+ and/or CK5/6+). When CK14 and p63 were added to the panel, two additional cases could be classified as basal-like. The majority of MBCs lacked PR, except 4/19 (21%) carcinomas with squamous metaplasia.

Conclusions: Our results demonstrate that MBCs show a basal-like phenotype, regardless of the type of metaplastic elements. Moreover, as these neoplasms frequently overexpress EGFR (57%), patients with MBC may benefit from treatment with anti-EGFR drugs.