Hi,
I am an Australian pathologist who has grown her own HER2 positive cancer. I have just finished my first round of TCH chemo.
Pleomorphic lobular carcinoma (PLC) was reported in the early 1990's, but pathologists have become more aware of the diagnosis in the last few years as the E-cadherin stain which helps pick which cancers are lobular and which are ductal became widely available.
Invasive PLC closely mimics invasive duct carcinoma and PLC in situ mimics DCIS. Invasive PLC is usually grade 3 and appears to behave similarly to grade 3 invasive duct carcinoma, and a bit worse than classic invasive lobular carcinoma which is almost always Grade 2.
Don't get too hung up on the "pleomorphic lobular " bit. It is a handle for pathologists to help with diagnosis. Until E-cadherin came along these cancers where often misdiagnosed as grade 3 invasive duct carcinoma.
PLC should be treated in the same way as all breast cancers are - on the basis of size, tumor grade, ER status, Her2 Status, node status, presence of distant spread etc.
LVI is important, if extensive, particularly increasing the risk of local recurrence and also as a factor in pushing an oncologist towards a particular type of chemo, or a radiation oncologist to give local radiation to chest and nodes.
In my opinion, invasive and in situ pleomorphic lobular carcinoma should be completely excised if feasible.
Low grade classic lobular carcinoma in situ (LCIS) can be wide spread and does not necessarily have to be excised (which can be hard to do without mastectomy and then it can turn up in your other breast anyway.) Classic (LCIS) is always ER+ and can be controlled by the other hormonal therapy, chemotherapy and radiation provided for the higher grade lesions. I would not have a double mastectomy for residual classic LCIS unless I had a very strong family history and my oncologist advised it.
Your oncologist will be able to provide you with information about your specific risks and best therapy. It just takes time to get it clear in your head.
See this site for an excellent book you can buy to help you in your journey.
http://www.breastcancertakingcontrol.com.au/
If you have any specific pathology questions, I'll do my best.
Aussie Girl