Bilateral breast ca is -

Lobular carcinoma (invasive) is frequently bilateral. Lobular carcinoma in situ in 20-40% cases are bilateral. Features of invasive lobular carcinoma of breast are : Histologic hallmark : pattern of single infiltrating tumor cells often only one cell in width or in loose clusters or sheets. Signet ring cells common Lobular carcinoma have a different pattern of metastasis compared to other breast cancers. metastases to the peritoneum, retroperitoneum, leptomeninges (Carcinomatous meningitis), the git, and the ovaries & uterus are frequently observed, these carcinomas are less likely to metastasize to lung and pleura.