Image of the Quarter (2015-7)
Lobular carcinoma with aberrant e cadherin and negative beta catenin
60 year old screener - core biopsy-confirmed carcinoma - excision.
Morphologically this is a lobular carcinoma and a solid variant subtype.
This is a x 20 view of the tumour showing classical pattern cytology and typical streaming. The 'mouse-over' shows a positive E Cadherin immunostain but
with a granular submembranous pattern (aberrant staining) rather than the crisp circumferential membrane staining seen in NST carcinomas and normal breast epithelium.
Further views of aberrant E cadherin staining. In the 'mouse-over' the crisp membrane pattern staining of normal epithelium can be seen in the bottom right hand corner.
These final views show aberrant E Cadherin staining and absent beta catenin staining on the 'mouse-over'. The crisp membrane stining of normal glands is seen in the bottom right hand corner of both images - an excellent internal control on the slide.
This is an unusual combination of immunostaining patterns in a lobular carcinoma. Most lobular carcinomas (90%) show absent E cadherin and cytoplasmic accumulation of clumps of beta catenin. Beta catenin is an important component of the cadherin cell adhesion complex and its absence in this case suggests some alternative molecular pathway in
action in the generation of Cadherin complexes which are failing to act as they should as evidenced by the aberrant E Cadherin staining pattern.