Abdominal organs (liver, kidney, spleen) are frequent targets of cancer cell invasion but their primary tumours are less known for their metastatic potential to other organs e.g. to the breast. Despite the known connection of the pathogenesis from breast cancer to liver metastasis, the study of the spread in the opposite direction has been neglected. The notion that breast cancer could be a metastasis besides being a primary tumour is based on rodents’ tumour models upon implantation of tumour cells under the capsule of the kidney or under the Glisson’s capsule of the liver of rats and mice. Tumour cells develop into a primary tumour at the site of subcutaneous implantation. The metastatic process starts with peripheral disruptions of blood vessels near the surface of primary tumours. Tumour cells released into the abdomen cross the apertures of the diaphragm, enter the thoracal lymph nodes and accumulate in parathymic lymph nodes. Abdominal colloidal carbon particles injected into the abdomen faithfully mimicked the migration of tumour cells and deposited in parathymic lymph nodes (PTNs). An explanation is provided why the connection between abdominal tumours and mammary tumours escaped attention, notably, parathymic lymph nodes in humans were referred to as internal mammary or parasternal lymph nodes. The apoptotic effect of Janus-faced cytotoxins is suggested to provide a new approach against the spread of abdominal primary tumours, and metastatic development.