Disseminated lobular carcinoma - a predominantly pleomorphic lobular carcinoma of the whole breast.

Contrary to the usual distribution of lobular carcinoma in situ in a few lobules or terminal ducts, a case of disseminated lobular carcinoma is described occupying all lobules of the whole breast. The tumor developed in the left breast of a 61-year-old woman with the clinical symptoms of an increasing diffuse induration. The proliferating cells were predominantly pleomorphic with hyperchromatic nuclei and loss of cell cohesion. In 690 slides examined the tumor cells in lobules and ducts revealed various stages of proliferation with transition to invasive small cell carcinoma in 15 different areas. This disseminated lobular carcinoma appears to be an advanced form of primary cancer multicentric in one breast and originating from the basal cells of the lobules and terminal ducts due to a general carcinogenic stimulus.