Hi Kellywilk and “welcome” to the club nobody wants to join. My doctors at Johns Hopkins say IDC with lobular features in NOT mixed type. It is IDC and some cells literally look a bit like lobular cancer cells but are not. They say prognosis and treatment goes just as regular IDC. Good luck to you. Take it day by day. Keep up posted

Hi Kellywilk.

I have triple negative bc that is IDC with lobular features. It is my understanding that imaging for IDC with lobular features can be difficult. Before I was diagnosed, the NP who performed the breast exam told me that there was no lump and to just go home because I didn’t have breast cancer. I insisted on a mammogram and the tech that performed the mammogram told me she didn’t think it was breast cancer because it didn’t look like typical breast cancer. Thankfully, the radiologist decided to do an ultrasound and biopsy. A few weeks later I was told I had stage 3/4 triple negative breast cancer. My MO does not believe it is necessary to have any thing other than once a year mammogram. I don’t agree with her, but I don’t know of any protocol that requires additional scans for IDC with lobular features. If anyone can point to an article on how to monitor IDC with lobular features, it would be much appreciated

I also have a mixed diagnosis even though my profile says IDC. The one article Shetland linked I've read before, in that IDC-L maybe a variant of IDC. E-cadherin I can not find on my pathology, so I don't know if it was positive or negative? Not sure it makes much difference treatment wise? My oncotype was 17. My sister has lobular type. Pretty sure I'm being treated as IDC.

Here's another study link. Copying the last paragraph. It is some interesting stuff, however my own personal non professional conclusion is that the "with lobular features" isn't that much of a clinical difference in your prognosis and treatment.

Mixed ductal‐lobular carcinomas: evidence for progression from ductal to lobular morphology - McCart Reed - 2018 - The Journal of Pathology - Wiley Online Library

This study demonstrates that the different morphological components present within an MDL tumour are clonally related and not the result of a collision of multiple independent tumours, thus supporting the idea that MDL tumours represent a distinct clinical and biological entity. We show that, in some cases, the divergence of the morphological components may occur early during tumour evolution (both DCIS and LCIS are present) or later during tumour progression (only DCIS detectable). The cases with late-occurring divergence may arise via a ductal-like pathway of progression, and these data emphasize the possibility that a lobular-like phenotype can arise via a modified ductal pathway. As previously detailed 3, the clinical conundrum surrounding a mixed tumour is that the good prognostic features of one component may have no prognostic value in the presence of a component with more aggressive features, regardless of which is the most conspicuous component. Clinically, there is little value in broadly categorizing MDLs into either lobular-like or ductal-like, and a more detailed assessment is required. Indeed, we have shown that the morphologically disparate regions harbour mutations in several breast cancer driver genes, which may predict targeted therapeutic options in the future. The evaluation of the true molecular profile of breast tumours is greatly influenced by tumour cellularity, and, critically in terms of discovery approaches, known proportions of morphologically distinct clones. The molecular analysis presented here highlights the genomic differences and similarities between the morphological regions of the MDLs, and contributes to our broader understanding of the genetic picture of breast cancer.

ctmbsikia, perhaps your onc needs to ask the pathologist to review your slides and say whether e-cadherin is present or not. Interesting that your sister's diagnosis was lobular. I have a close relative who, like me, has a lobular diagnosis. Also fyi, ILC often has a midde-range Oncotype score.